bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrical characterization of all-epitaxial Fe/GaN(0001) Schottky tunnel contacts
Authors: Fernández-Garrido Sergio , Ubben Kai U. , Herfort Jens , Gao Cunxu , Brandt Oliver
Published: July 2012

We analyze the properties of Fe Schottky contacts prepared in situ on n-type GaN(0001) by molecular beam epitaxy. In particular, we investigate the suitability of these epitaxial Fe layers for electrical spin injection. Current-voltage-temperature measurements demonstrate pure field emission for Fe/GaN:Si Schottky diodes with [Si]=5×1018 cm−3. The Schottky barrier height of the clean, epitaxial Fe/GaN interface is determined by both current-voltage-temperature and capacitance-voltage techniques to be (1.47±0.09)eV.
Cost modeling approach and economic analysis of biomass gasification integrated solid oxide fuel cell systems
Authors: Kempegowda Rajesh S. , Skreiberg Øyvind , Tran Khanh-Quang
Published: July 2012

This paper presents a cost modeling approach and the economic feasibility for selected plant configurations operating under three modes: air gasification, mixed air-steam gasification, and steam gasification combined cycle solid oxide fuel cell (SOFC) systems. In this study, three cases of biomass gasification integrated SOFC without combined cycle (base case 1) are compared with biomass gasification integrated SOFC-gas turbine (GT) with heat recovery steam generator (HRSG) hybrid configuration (case 2) and biomass gasification integrated SOFC-steam turbine (ST) cycle (case 3) for biomass feed stock. The plant design cases of integrated biomass gasification processes, SOFC, and combined cycles are investigated primarily employing aspen plus™ flow sheeting models. Based on the mass and energy balance results of the system simulations, the economic model calculates the size and cost estimates for the plant configuration equipments. Detailed purchase cost estimations for each piece of equipments and the corresponding total bare module cost were established based on the bare module factor, and the total direct permanent investment were established. The calculated direct permanent investment was used for economic feasibility analysis of the cogeneration plant configuration. The economic feasibility decision parameters, such as purchase cost estimations, total specific plant cost per kW, the financial net present value (FNPV), internal rate of return, and benefit to cost ratio for the system configurations were compared for three design cases. The results shows that the cost of the steam gasification system is shown to be highest compared to the mixed air steam gasification system and air gasification system due to the higher hydrogen production. Other than the SOFC and gasification costs, a significant cost towards the heat exchangers is about 15% to 20% of the total equipment purchase cost. The specific plant cost for the air gasification varied from the 16 600 US$/kW to 19 200 US$/kWe. For the case of biomass gasification-integrated SOFC-GT configuration, the major cost portions are shared by the SOFC, HRSG, and gasifier. The HRSG equipment shared a cost portion of 25% to 30% for all the operating modes. The cost is decreased with a similar trend as that of steam, mixed air-steam and air gasification systems. For the case of biomass gasification integrated with SOFC-ST configuration, the total equipment purchase cost decreases at a rate of 15% to 20% for both mixed air steam and air gasification system. Plant specific cost for the steam gasification mode varied from 15 200 to 17 200 US $/kW which is significantly very high.
Blue light emitting diode internal and injection efficiency
Authors: Titkov Ilya E. , Sannikov Denis A. , Park Young-Min , Son Joong-Kon
Published: July 2012

A simple experimental method of light emitting diode (LED) injection efficiency (IE) determination was suggested. IE and internal quantum efficiency (IQE) calculation is an actual and difficult problem in LED science. In this paper IE and IQE of blue LEDs were determined separately. The method is based on electroluminescence data fitting by the modified rate equation model. Efficiency droop caused by Auger recombination and poor injection were taken into account. Only one reasonable assumption was accepted during the calculations: IE tends to 1 at low current densities.
A Reward-Recovery Study to Estimate Tagged-Fish Reporting Rates by Idaho Anglers
Authors: Meyer Kevin A. , Elle F. Steven , Lamansky James A. , Mamer Elizabeth R. J. M. , Butts Arthur E.
Published: July 2012

From 2006 to 2009, we tagged and released 22,202 fish with T-bar anchor tags valued at US$0 to $200 if returned. Our intent was to assess angler tag reporting rates in Idaho and to determine whether reporting rates declined over time or differed between species. A total of 4,643 tags were reported by anglers. Assuming a reporting rate of 100% for $200 tags, weighted mean reporting rates were 54.2% for $0 tags, 69.7% for $10 tags, 91.7% for $50 tags, and 98.9% for $100 tags. By combining $100 and $200 as high-reward tags to increase sample size, nonreward tag-reporting rate was 54.5%. Tag reporting rates varied between groups of species, being highest for harvest-oriented species, both coolwater and warmwater, such as walleye Sander vitreus ($0 = 68.3%), yellow perch Perca flavescens (58.5%), and crappie Pomoxis spp. (59.7%), and lowest for largemouth bass Micropterus salmoides (39.2%). There was little variation in tag-reporting rates over time, weighted means being 53, 56, 50, and 56% from 2006 to 2009, but reporting rate did appear to decline for some species (most notably crappies). There was some evidence of a slight violation of the assumption of independence in tag-reporting, indicated by nonreward tag-reporting rates being marginally higher for anglers reporting both nonreward and reward tags than for those reporting only one or the other (signifying possible batch-reporting of tags). No batch-reporting was evident from differences in reporting rates for households reporting multiple tags compared with those reporting only one tag. Our results suggest that anglers in Idaho reported over half the nonreward tags they encountered, but rates appeared to vary among species, and this knowledge is being used to estimate angler exploitation across Idaho.

Received November 22, 2011; accepted April 5, 2012
Room Temperature Ferromagnetism in Ga1−xHoxN (x=0.0 and 0.05) Diluted Magnetic Semiconductor Thin Films
Authors: Rai Ghulam Murtaza , Iqbal Muhammad Azhar , Xu Yong-bing , Will Iain Gordon , Mahmood Qasim
Published: July 2012

Holmium doped GaN diluted magnetic semiconductor thin films have been prepared by thermal evaporation technique and subsequent ammonia annealing. X-ray diffraction measurements reveal all peaks belong to the purely hexagonal wurtzite structure. Surface morphology and composition analysis were carried out by scanning electron microscopy and energy dispersive spectroscopy respectively. The room temperature ferromagnetic properties of Ga1−xHoxN (x=0.0, 0.05) films were analyzed using vibrating sample magnetometer at room temperature. Magnetic measurements showed that the undoped films (i.e. GaN) exhibited diamagnetic behavior, while the Ho-doped (Ga0.95Ho0.05N) film exhibited a ferromagnetic behavior.
Fouling-release Property of Water-filled Porous Elastomers
Authors: Xie Lai-yong , Hong Fei , He Chuan-xin , Liu Jian-hong , Wu Chi
Published: July 2012

Since the fouling-releasing ability of silicone elastomers increased as their modulus decreases, we designed and prepared composites with embedded tiny NaCl crytals that were soluble after their immersion in water, resulting in water-filled porous elastomers. The scanning electron microscope images confirmed such a designed water-filling porous structure. The existence of many micro-drops of water in these specially designed elastomers decreased the shear storage modulus and increased the loss factors. The decrease of shear modulus plays a leading role here and is directly related to a lower critical peeling-off stress of a pseudo-barnacle on them. Therefore, such a novel preparation with cheap salts instead of an expensive silicone provides a better way to make fouling-release paints with a lower modulus, a lower critical peeling-off stress and a better fouling-release property without a significant decrease of the cross-linking density.
PEO-b-P4VP/Yttrium Hydroxide Hybrid Nanotubes as Supporter for Catalyst Gold Nanoparticles
Authors: Yang Qian , Chen Dao-yong
Published: July 2012

The adsorption of poly (ethylene oxide)-b-poly(4-vinylpyridine)(PEO-b-P4VP) micelles onto the surface of yttrium hydroxide nanotubes (YNTs) resulted in the hybrid nanotubes with a dense P4VP inner layer and a stretched PEO outer layer surrounding YNTs. The dense P4VP layer was further stabilized by the crosslinking using 1,4-dibromobutane as the crosslinker. Then, the crosslinked hybrid nanotubes (CHNTs) were used as a novel nano supporter for loading the catalyst gold nanoparticles (GNPs) within the crosslinked P4VP layer. The resultant GNPs/CHNTs (GNTs loaded on CHNTs) were applied to catalyze the reduction reaction of p-nitrophenol. The results indicate that this novel nano supporter has advantages such as good dispersity in the suspension, high capacity in loading GNPs (0.87 mmol/g), high catalytic activity of the loaded GNPs (12.9 μmol−1min−1), and good reusability of GNTs/CHNTs.
Maximum Hydrogen Production by Autothermal Steam Reforming of Bio-oil With NiCuZnAl Catalyst
Authors: Yan Shi-zhi , Zhai Qi , Li Quan-xin
Published: July 2012

Autothermal steam reforming (ATR) of bio-oil, which couples the endothermic steam reforming reaction with the exothermic partial oxidation, offers many advantages from a technical and economic point of view. Effective production of hydrogen through ATR of bio-oil was performed at lower temperature with NiCuZnAl catalyst. The highest hydrogen yield from bio-oil reached 64.3% with a nearly complete bio-oil conversion at 600 °C, the ratio of steam to carbon fed (S/C) of 3 and the oxygen to carbon ratio (O/C) of 0.34. The reaction conditions in ATR including temperature, O/C, S/C and weight hourly space velocity can be used to control both hydrogen yield and products distribution. The comparison between the ATR and common steam reforming of bio-oil was studied. The mechanism of the ATR of bio-oil was also discussed.
Dnt1 acts as a mitotic inhibitor of the spindle checkpoint protein dma1 in fission yeast
Authors: Wang Yamei , Li Wen-zhu , Johnson Alyssa E. , Luo Zhou-qing , Sun Xue-li , Feoktistova Anna , McDonald W. Hayes , McLeod Ian , Yates John R. , Gould Kathleen L. , McCollum Dannel , Jin Quan-wen
Published: July 2012

The Schizosaccharomyces pombe checkpoint protein Dma1 couples mitotic progression with cytokinesis and is important in delaying mitotic exit and cytokinesis when kinetochores are not properly attached to the mitotic spindle. Dma1 is a ubiquitin ligase and potential functional relative of the human tumor suppressor Chfr. Dma1 delays mitotic exit and cytokinesis by ubiquitinating a scaffold protein (Sid4) of the septation initiation network, which, in turn, antagonizes the ability of the Polo-like kinase Plo1 to promote cell division. Here we identify Dnt1 as a Dma1-binding protein. Several lines of evidence indicate that Dnt1 inhibits Dma1 function during metaphase. First, Dnt1 interacts preferentially with Dma1 during metaphase. Second, Dma1 ubiquitin ligase activity and Sid4 ubiquitination are elevated in dnt1∆ cells. Third, the enhanced mitotic defects in dnt1Δ plo1 double mutants are partially rescued by deletion of dma1+, suggesting that the defects in dnt1∆ plo1 double mutants are attributable to excess Dma1 activity. Taken together, these data show that Dnt1 acts to restrain Dma1 activity in early mitosis to allow normal mitotic progression.
Structure and functional studies of N-terminal Cx43 mutants linked to oculodentodigital dysplasia
Authors: Shao Qing , Liu Qin , Lorentz Robert , Gong Xiang-Qun , Bai Donglin , Shaw Gary S. , Laird Dale W.
Published: July 2012

Mutations in the gene encoding connexin-43 (Cx43) cause the human development disorder known as oculodentodigital dysplasia (ODDD). In this study, ODDD-linked Cx43 N-terminal mutants formed nonfunctional gap junction–like plaques and exhibited dominant-negative effects on the coupling conductance of coexpressed endogenous Cx43 in reference cell models. Nuclear magnetic resonance (NMR) protein structure determination of an N-terminal 23–amino acid polypeptide of wild-type Cx43 revealed that it folded in to a kinked α-helical structure. This finding predicted that W4 might be critically important in intramolecular and intermolecular interactions. Thus we engineered and characterized a W4A mutant and found that this mutant formed a regular, nonkinked α-helix but did not form functional gap junctions. Furthermore, a G2V variant peptide of Cx43 showed a kinked helix that now included V2 interactions with W4, resulting in the G2V mutant forming nonfunctional gap junctions. Also predicted from the NMR structures, a G2S mutant was found to relieve these interactions and allowed the protein to form functional gap junctions. Collectively, these studies suggest that the nature of the mutation conveys loss of Cx43 function by distinctly different mechanisms that are rooted in the structure of the N-terminal region.
Fast and accurate read alignment for resequencing
Authors: Mu John C. , Jiang Hui , Kiani Amirhossein , Mohiyuddin Marghoob , Bani Asadi Narges , Wong Wing H.
Published: July 2012

Motivation: Next-generation sequence analysis has become an important task both in laboratory and clinical settings. A key stage in the majority sequence analysis workflows, such as resequencing, is the alignment of genomic reads to a reference genome. The accurate alignment of reads with large indels is a computationally challenging task for researchers.

Results: We introduce SeqAlto as a new algorithm for read alignment. For reads longer than or equal to 100 bp, SeqAlto is up to 10 × faster than existing algorithms, while retaining high accuracy and the ability to align reads with large (up to 50 bp) indels. This improvement in efficiency is particularly important in the analysis of future sequencing data where the number of reads approaches many billions. Furthermore, SeqAlto uses less than 8 GB of memory to align against the human genome. SeqAlto is benchmarked against several existing tools with both real and simulated data.

Availability: Linux and Mac OS X binaries free for academic use are available at http://www.stanford.edu/group/wonglab/seqalto

Contact:  whwong@stanford.edu
Regulating the Employment Relationship in Professional Team Sports
Authors: O’LEARY LEANNE
Published: July 2012

A sporting code’s governing body is a private association of members that frequently exercises monopoly power in the sport over which it presides. In a professional team sports competition, a sporting code’s governing body may prescribe standard terms and conditions of employment, organise the competition and adopt regulatory measures which directly or indirectly affect the employment interests of players. In most relevant circumstances, a sporting code’s governing body is not obliged to inform, consult with or seek the agreement of players prior to the implementation of a regulatory measure that directly or indirectly affects a player’s employment. Strengthening the regulation of professional sport through competition law could balance the employment interests of players with the commercial and regulatory interests in a professional sports competition. Establishing a direct employment relationship between players and the sporting code’s governing body would also assist.
Human population size, environment, and health
Authors: McMichael A.J. , Powles J.W.
Published: July 2012

The number of people has increased in a series of steps by around five orders of magnitude over the past 100 000 years as geographical dispersal and cultural changes expanded access to food and other resources. The last 10-fold increase has occurred in just over two centuries....
Palliative care
Authors: Wee Bee
Published: July 2012

Palliative care addresses the physical, psychological, social, and spiritual needs of someone with advanced, progressive, and fatal disease. Good symptom control requires meticulous assessment, effective two-way communication, and the wise use of drugs, supported by other therapeutic interventions.

Common symptoms are (1) pain—one of the most feared symptoms in patients with advanced malignant disease; managed with disease modifying treatments, nondrug measures (e.g. heat pads), and/or analgesics (see also ...
Apoptosis in health and disease
Authors: Wyllie Andrew H. , Arends Mark J.
Published: July 2012

Apoptosis is the process by which single cells die in the midst of living tissues. It is responsible for most—perhaps all—of the cell-death events that occur during the formation of the early embryo and the sculpting and moulding of organs. Apoptotic cell death continues to play a critical role in the maintenance of cell numbers in those tissues in which cell turnover persists into adult life, such as the epithelium of the gastrointestinal tract, the bone marrow, and lymphoid system including both B- and T-cell lineages. Apoptosis is the usual mode of death in the targets of natural killer (NK) cells and cytotoxic T-cells, and in involution and atrophy induced by hormonal and other stimuli. It also appears in the reaction of many tissues to injury, including mild degrees of ischaemia, exposure to ionizing and ultraviolet radiation, or treatment with cancer chemotherapeutic drugs. Excessive or too little apoptosis play a significant part in the pathogenesis of autoimmunity, infectious disease, AIDS, stroke, myocardial disease, and cancer. When cancers regress, apoptosis is part of the mechanism involved. Here the cellular processes and molecular mechanisms of apoptosis are set out, together with a conspectus of its involvement in many diseases....
Herpesviruses (excluding Epstein–Barr virus)
Authors: Sissons J.G.P.
Published: July 2012

Eight human herpesviruses, all with a linear double-stranded DNA genome and divided into alpha-, beta-, and gamma-subfamilies on the basis of genomic and biological properties, share the capacity to produce latent infection. The diseases they cause may result from primary infection, or reactivation of the virus from latency, and tend to be more severe in immunosuppressed patients. Diagnosis of the various herpesvirus infections may be made on clinical grounds alone, by culture or demonstration of viral particles by electron microscopy of relevant samples, by serological testing, or (increasingly) by PCR-based tests....
Alphaviruses
Authors: Ooi E.E. , Petersen L.R. , Gubler D.J.
Published: July 2012

There are 29 registered alphaviruses belonging to the family Togaviridae, 16 of which are known to cause human infection. They are RNA viruses with global geographical distribution and complex transmission cycles between wild or domestic animals or birds and one or more mosquito species; humans are infected by mosquito bites. They cause a spectrum of clinical manifestations ranging from nonspecific febrile illness to acute encephalitis and death. Diagnosis of infection is made serologically by detection of IgM and IgG antibodies, virus isolation, and polymerase chain reaction, or by immunohistochemistry on tissue samples....
Papillomaviruses and polyomaviruses
Authors: Viscidi Raphael P. , Shah Keerti V.
Published: July 2012

Papillomaviruses and polyomaviruses are small, nonenveloped, double-stranded DNA viruses.

There are over 100 human papillomavirus (HPV) types that infect epithelia of skin and mucous membranes. They infect only humans, and cause conditions including the following:

Skin warts and verrucas—caused by types 1 and 2; infection initiated when, after e.g. minor skin abrasions, the basal cells of the epithelium come in contact with infectious virus....
Typhoid and paratyphoid fevers
Authors: Parry C.M. , Basnyat Buddha
Published: July 2012

Typhoid and paratyphoid fever (the enteric fevers) are caused by specific serovars of the Gram-negative bacillus, Salmonella enterica. Sources of typhoid transmission are excreting chronic or convalescent carriers and the acutely infected, with transmission occuring through contamination by carriers of food or water by effluents containing infected urine or faeces. There are an estimated 27 million cases of enteric fever in the world each year, almost all in the developing world, with about 200 000 deaths....
Clostridium difficile
Authors: Bartlett John G.
Published: July 2012

Clostridium difficile is a Gram-positive spore-forming anaerobic bacillus found in the environment. Its spores are part of the colonic flora in about 2 to 3% of healthy adults, with colonization rates increasing during hospitalization to 20 to 40%. Disease occurs when the organism shifts to its replicating vegetative form with toxin (A and B) production, this typically happening when there is inhibition of the competing colonic flora by antibiotics. ...
Nonvenereal endemic treponematoses: yaws, endemic syphilis (bejel), and pinta
Authors: Warrell David A.
Published: July 2012

The endemic treponematoses are chronic, granulomatous diseases caused by morphologically and serologically identical spirochaetes of the genus Treponema. They are spread by intimate but nonsexual contact and sometimes by fomites, mainly among children. Treponema pallidum subsp. pertenue causing yaws (framboesia), T. pallidum subsp. endemicum causing endemic syphilis (bejel) and ...
Pneumocystis jirovecii
Authors: Miller Robert F. , Huang Laurence
Published: July 2012

The ascomycete fungus Pneumocystis jirovecii (previously called Pneumocystis carinii) is the cause of pneumocystis pneumonia (PCP) in humans, which occurs largely among people with impaired CD4+ T-lymphocyte function or numbers, e.g those infected with HIV, or organ transplant recipients taking therapeutic immunosuppressive agents. The organism is restricted to humans, and disease is now thought to arise from ...
Cysticercosis
Authors: Garcia Hector H. , Gilman Robert H.
Published: July 2012

Cysticercosis, infection by larvae of the pork tapeworm Taenia solium (see Chapter 7.10.2), is the commonest helminthic infection of the human central nervous system. It accounts for up to 30% of all seizures and epilepsy in endemic countries, and travel and immigration now lead to its more frequent presentation in industrialized countries....
Liver fluke infections
Authors: Grove David I.
Published: July 2012

Clonorchis (syn. Opisthorchis) sinensis is a fluke (flatworm) acquired by ingestion of undercooked freshwater fish in eastern Asia. Larvae in the duodenum enter the biliary tree through the sphincter of Oddi and mature. Most patients are asymptomatic, but there may be right upper abdominal discomfort, and infection can be complicated by bacterial cholangitis and there is an increased risk of cholangiocarcinoma. Diagnosis is suggested by finding eggs in faeces or in duodenal aspirates, but can only be confirmed by examination of adult flukes. Treatment is with praziquantel....
Diseases of high terrestrial altitudes
Authors: Pollard Andrew J. , Basnyat Buddha , Murdoch David R.
Published: July 2012

Ascent to altitudes above 2500 m leads to exposure to hypobaric hypoxia. This affects performance on first arrival at high altitude and disturbs sleep, but physiological changes occur over time to defend arterial and tissue oxygenation and allow the individual to adjust. This process of acclimatization includes (1) an increase in the rate and depth of breathing; and (2) an increase in red cell mass, and in red cell 2,3-diphosphoglycerate. Acclimatization is no longer possible at extreme altitude (>5800 m) and the exposed individual will gradually deteriorate....
Acquired metabolic disorders and the nervous system
Authors: Scolding Neil , Marsden C.D.
Published: July 2012

Case History—A 65 yr old man presenting with poor memory a few months after a surgical admission.

Case History—An 80 yr old man presenting with falls, reduced mobility, muscular weakness and peripheral neuropathy.

Case History—A 34 yr old woman presenting with twitching of the face and jerking of the legs and arms...
Structure and function of muscle
Authors: Hanna M.G.
Published: July 2012

Abstracts and keywords to be supplied.
General introduction
Authors: Sharpe Michael
Published: July 2012

All physicians who deal with patients experience situations where psychiatric knowledge, skills, and attitudes are relevant. This section of the book provides (1) guidance on how to take a psychiatric history and perform a mental state examination in a medical patient; (2) information about those psychiatric diagnoses most relevant to general medical practice; (3) practical advice on the management of depression and anxiety when it coexists with disease, medically unexplained somatic symptoms, deliberate self-harm, and acute behavioural problems; and (4) detailed information on the common and clinically important problems of alcohol and substance misuse....
Genitourinary problems
Authors: Watson Max , Lucas Caroline , Hoy Andrew , Wells Jo
Published: July 2012

This chapter focuses on the anatomy and physiology of the bladder and micturition. It covers bladder wall, sphincter active urethra, nerve supply, bladder pain and its treatment, blood supply of the bladder, urinary tract infection (UTI), renal pain, ureteric colic, pelvic pain, urinary retention, ureteric obstruction, urinary incontinence, haematuria, catheterization, genitourinary fistulae, vesicoenteric fistulae, vesicovaginal fistulae, and sexual health in advanced disease.
Palliative care in non-malignant respiratory disease
Authors: Watson Max , Lucas Caroline , Hoy Andrew , Wells Jo
Published: July 2012

This chapter covers the potential requirement for palliative care in end-stage pulmonary disease, terminal symptoms, quality of life, and survival of patients with end-stage pulmonary disease, chronic bronchitis and emphysema, and pneumothorax and pleural disease.
AIDS in adults
Authors: Watson Max , Lucas Caroline , Hoy Andrew , Wells Jo
Published: July 2012

This chapter covers the clinical features of AIDS in adults, natural history, and the effects and limitations of highly active antiretroviral therapy (HAART).
The contribution to palliative care of allied health professions
Authors: Watson Max , Lucas Caroline , Hoy Andrew , Wells Jo
Published: July 2012

This chapter contains a very brief introduction to the contribution to palliative care of allied health professions.
Complementary and alternative medicine in palliative care
Authors: Watson Max , Lucas Caroline , Hoy Andrew , Wells Jo
Published: July 2012

This chapter on complementary and alternative medicine in palliative care covers alternative medical systems, mind-body therapies, biologically-based practices, and manipulative and body-based therapies.
Neurodiagnostic tools
Authors: Forsyth Rob , Newton Richard
Published: July 2012

Principles of investigation 52

Principles of neuroradiology 54

Neuroradiological anatomy 64

Brainstem anatomy 69

Principles of neurophysiology 70

Peripheral neurophysiological tests 76

Neurophysiological testing of central sensory pathways 82

Specialist investigations 85

Practical procedures 94

Neuropsychological testing 99

This subject tends to bring some people out in a rash (...
First Report of Meloidogyne enterolobii Infecting Euphorbia punicea in Florida
Authors: Han H. , Brito J. A. , Dickson D. W.
Published: July 2012

Euphorbia punicea (Euphorbiaceae), commonly known as Jamaican poinsettia, is an evergreen shrub with dark green leaves and flashy red bracts. Bracts are sharply contrasted by rosettes of dark green leaves and can be observed in early summer, spring, fall, and winter. This shrub, native to Jamaica, is suitable in southern climates both in the landscape and as a seasonal patio container plant. Outdoors, the plants can reach as high as 5 meters. In January of 2012, E. punicea plants growing in an ornamental nursery in Dade Co., Florida, were observed with stunted growth and yellowing leaves. Root systems of affected plants were collected and sent to the Florida Department of Agriculture and Consumer Services, Nematology Laboratory, Gainesville, FL. Root systems showing symptoms of root-knot nematode infections were heavily galled and had already started rotting. Galls were observed in the primary, secondary, and tertiary roots. Species identification was initially performed using morphology and morphometrics. The morphology of the perineal patterns and measurements of selected characters of the second-stage juveniles fit those of the original description for M. enterolobii (3). The nematode species identification was confirmed using PCR to amplify mtDNA with the C2F3/1108 primer set (1) and a species-specific SCAR primer set, MK7-F/MK7-R (2). The PCR products were approximately 700 bp for mtDNA and approximately 520 bp for the SCAR, which were identical to those previously reported for M. enterolobii (1, 2). Sanitation practices should be implemented to avoid the spread of this nematode species within and between ornamental nurseries. Planting material should be produced in media free of this pathogen to avoid its introduction into uninfested nurseries and landscape areas. M. enterolobii has a wide host range, including cover and vegetable crops, fruit trees, herbs, and ornamental and weed plants. To our knowledge, this is the first report worldwide of E. punicea as a host of M. enterolobii.

References: (1) T. O. Powers et al. J. Nematol. 37:226, 2005. (2) M. S. Tigano et al. Plant Pathol. 59:1054, 2010. (3) B. Yang and J. D. Eisenback. J. Nematol. 15:381, 1983.
Relevance of the sterilization-induced effects on the properties of different hydroxyapatite nanoparticles and assessment of the osteoblastic cell response
Authors: Santos C. , Gomes P. S. , Duarte J. A. , Franke R. P. , Almeida M. M. , Costa M. E. V. , Fernandes M. H.
Published: July 2012

Hydroxyapatite (Hap) is a calcium phosphate with a chemical formula that closely resembles that of the mineral constituents found in hard tissues, thereby explaining its natural biocompatibility and wide biomedical use. Nanostructured Hap materials appear to present a good performance in bone tissue applications because of their ability to mimic the dimensions of bone components. However, bone cell response to individual nanoparticles and/or nanoparticle aggregates lost from these materials is largely unknown and shows great variability. This work addresses the preparation and characterization of two different Hap nanoparticles and their interaction with osteoblastic cells. Hap particles were produced by a wet chemical synthesis (WCS) at 37°C and by hydrothermal synthesis (HS) at 180°C. As the ultimatein vivoapplications require a sterilization step, the synthesized particles were characterized ‘as prepared’ and after sterilization (autoclaving, 120°C, 20 min). WCS and HS particles differ in their morphological (size and shape) and physicochemical properties. The sterilization modified markedly the shape, size and aggregation state of WCS nanoparticles. Both particles were readily internalized by osteoblastic cells by endocytosis, and showed a low intracellular dissolution rate. Concentrations of WCS and HS particles less than 500 μg ml−1did not affect cell proliferation, F-actin cytoskeleton organization and apoptosis rate and increased the gene expression of alkaline phosphatase and BMP-2. The two particles presented some differences in the elicited cell response. In conclusion, WCS and HS particles might exhibit an interesting profile for bone tissue applications. Results suggest the relevance of a proper particle characterization, and the interest of an individual nanoparticle targeted research.
Structural analysis of the human SYCE2–TEX12 complex provides molecular insights into synaptonemal complex assembly
Authors: Davies Owen R. , Maman Joseph D. , Pellegrini Luca
Published: July 2012

The successful completion of meiosis is essential for all sexually reproducing organisms. The synaptonemal complex (SC) is a large proteinaceous structure that holds together homologous chromosomes during meiosis, providing the structural framework for meiotic recombination and crossover formation. Errors in SC formation are associated with infertility, recurrent miscarriage and aneuploidy. The current lack of molecular information about the dynamic process of SC assembly severely restricts our understanding of its function in meiosis. Here, we provide the first biochemical and structural analysis of an SC protein component and propose a structural basis for its function in SC assembly. We show that human SC proteins SYCE2 and TEX12 form a highly stable, constitutive complex, and define the regions responsible for their homotypic and heterotypic interactions. Biophysical analysis reveals that the SYCE2–TEX12 complex is an equimolar hetero-octamer, formed from the association of an SYCE2 tetramer and two TEX12 dimers. Electron microscopy shows that biochemically reconstituted SYCE2–TEX12 complexes assemble spontaneously into filamentous structures that resemble the known physical features of the SC central element (CE). Our findings can be combined with existing biological data in a model of chromosome synapsis driven by growth of SYCE2–TEX12 higher-order structures within the CE of the SC.
Tat has a dual role in simian immunodeficiency virus transcription
Authors: van der Velden Gisela J. , Vink Monique A. , Berkhout Ben , Das Atze T.
Published: July 2012

Tat has a pivotal role in human and simian immunodeficiency virus (HIV and SIV) replication because it stimulates transcription by binding to the trans-activator response (TAR) element. In addition, several other Tat functions have been proposed. Most studies have focused on HIV-1 Tat and much less is known about SIV Tat. An SIVmac239 variant was constructed previously in which the Tat–TAR transcription mechanism is functionally replaced by the doxycycline-inducible Tet-On gene expression mechanism (SIV-rtTA). In this study, SIV-rtTA variants were used to analyse the functions of SIV Tat. It was shown that Tat-minus SIV-rtTA variants replicated efficiently in PM1 T-cells, ruling out an additional essential Tat function. Nevertheless, replication was suboptimal in other cells, and evolutionary pressure to repair Tat expression was documented. It was demonstrated that SIV-rtTA required Tat for optimal gene expression, despite the absence of the Tat–TAR axis. This Tat effect was lost upon replacement of the long terminal repeat promoter region by a non-related promoter. These results indicate that Tat can activate SIV transcription via TAR RNA and U3 DNA elements but has no other essential function in replication in cultured cells. The experiments were limited to cell lines and PBMCs, and did not exclude an accessory Tat function under specific conditions or in vivo.
Characterization of a model of lethal dengue virus 2 infection in C57BL/6 mice deficient in the alpha/beta interferon receptor
Authors: Orozco Susana , Schmid Michael A. , Parameswaran Poornima , Lachica Ruben , Henn Matthew R. , Beatty Robert , Harris Eva
Published: July 2012

Dengue virus (DENV) causes dengue fever and dengue haemorrhagic fever/dengue shock syndrome, both considered major public-health problems worldwide. We generated a lethal DENV-2 strain (D220) by 10 additional cycles of subcutaneous inoculation of mice with supernatant from mosquito cells infected with the previously characterized strain D2S10, followed by harvesting of serum. D220 induces mortality at ten-fold lower doses than D2S10 in mice lacking only the alpha/beta interferon (IFN-α/β) receptor in C57BL/6 or 129 backgrounds under both non-enhanced and antibody-enhanced conditions. Sequence analysis of the complete viral genome revealed five amino acid changes between D220 and D2S10, of which two (K122I in envelope and V115A in NS4B) appear to account for the observed phenotypic differences between the viruses. By causing mortality at lower doses in C57BL/6 mice lacking only the IFN-α/β receptor, D220 constitutes an improved tool for study of DENV-induced pathogenesis, as well as for testing potential vaccines and antiviral drugs against DENV.
Transcription initiation by human RNA polymerase II visualized at single-molecule resolution
Authors: Revyakin Andrey , Zhang Zhengjian , Coleman Robert A. , Li Yan , Inouye Carla , Lucas Julian K. , Park Sang-Ryul , Chu Steven , Tjian Robert
Published: July 2012

Forty years of classical biochemical analysis have identified the molecular players involved in initiation of transcription by eukaryotic RNA polymerase II (Pol II) and largely assigned their functions. However, a dynamic picture of Pol II transcription initiation and an understanding of the mechanisms of its regulation have remained elusive due in part to inherent limitations of conventional ensemble biochemistry. Here we have begun to dissect promoter-specific transcription initiation directed by a reconstituted human Pol II system at single-molecule resolution using fluorescence video-microscopy. We detected several stochastic rounds of human Pol II transcription from individual DNA templates, observed attenuation of transcription by promoter mutations, observed enhancement of transcription by activator Sp1, and correlated the transcription signals with real-time interactions of holo-TFIID molecules at individual DNA templates. This integrated single-molecule methodology should be applicable to studying other complex biological processes.
An evaluation of the ability of leucocyte depletion filters to remove components of amniotic fluid*
Authors: Campbell J. P. , Mackenzie M. J. , Yentis S. M. , Sooranna S. R. , Johnson M. R.
Published: July 2012

Haemorrhage remains an important cause of maternal mortality worldwide. Cell salvage carries a theoretical risk of amniotic fluid embolus syndrome and is too expensive for use in many parts of the world. To explore cheaper options, we investigated whether a leucocyte depletion filter alone removes components of pure amniotic fluid. Amniotic fluid was collected from 10 women during elective caesarean section and passed through a LeukoGuard® RS filter. Pre‐ and post‐filtration samples were compared in the laboratory. Lamellar bodies and fetal squames were almost completely removed (filtration efficacy 96.6% and 99.9%, respectively; p < 0.0001 and <0.0004), and hair was completely removed (p = 0.002). Filtration had no effect on concentrations of α‐fetoprotein, tissue factor or endothelin‐1, or on the presence of meconium or vernix. Additional work is required to evaluate whether cell salvage using filtration alone may be useful in maternal haemorrhage in the developing world.
Pharmacodynamics, pharmacokinetics and safety of GSK2190915, a novel oral anti‐inflammatory 5‐lipoxygenase‐activating protein inhibitor
Authors: Bain Gretchen , King Christopher D. , Schaab Kevin , Rewolinski Melissa , Norris Virginia , Ambery Claire , Bentley Jane , Yamada Masanori , Santini Angelina M. , van de Wetering de Rooij Jeroen , Stock Nicholas , Zunic Jasmine , Hutchinson John H. , Evans Jilly F.
Published: July 2012

Aim

To assess the pharmacokinetics, pharmacodynamics, safety and tolerability of the 5‐lipoxygenase‐activating protein inhibitor, GSK2190915, after oral dosing in two independent phase I studies, one in Western European and one in Japanese subjects, utilizing different formulations.

Method

Western European subjects received single (50–1000 mg) or multiple (10–450 mg) oral doses of GSK2190915 or placebo in a dose‐escalating manner. Japanese subjects received three of four GSK2190915 doses (10–200 mg) plus placebo once in a four period crossover design. Blood samples were collected for GSK2190915 concentrations and blood and urine were collected to measure leukotriene B4 and leukotriene E4, respectively, as pharmacodynamic markers of drug activity.

Results

There was no clear difference in adverse events between placebo and active drug‐treated subjects in either study. Maximum plasma concentrations of GSK2190915 and area under the curve increased in a dose‐related manner and mean half‐life values ranged from 16–34 h. Dose‐dependent inhibition of blood leukotriene B4 production was observed and near complete inhibition of urinary leukotriene E4 excretion was shown at all doses except the lowest dose. The EC50 values for inhibition of LTB4 were 85 nm and 89 nm in the Western European and Japanese studies, respectively.

Conclusion

GSK2190915 is well‐tolerated with pharmacokinetics and pharmacodynamics in Western European and Japanese subjects that support once daily dosing for 24 h inhibition of leukotrienes. Doses of ≥50 mg show near complete inhibition of urinary leukotriene E4 at 24 h post‐dose, whereas doses of ≥150 mg are required for 24 h inhibition of blood LTB4.
Application of wood ash accelerates soil respiration and tree growth on drained peatland
Authors: Moilanen M. , Hytönen J. , Leppälä M.
Published: July 2012

Forested peatlands contain large pools of terrestrial carbon. As well as drainage, forest management such as fertilizer application can affect these pools. We studied the effect of wood ash (application rates 0, 5 and 15 t ha−1) on the heterotrophic soil respiration (CO2 efflux), cellulose decomposition, soil nutrients, biomass production and amount of C accumulated in a tree stand on a pine‐dominated drained mire in central Finland. The ash was spread 13 years before the respiration measurements. The annual CO2 efflux was statistically modelled using soil temperature as the driving variable. Wood ash application increased the amounts of mineral nutrients of peat substantially and increased soil pH in the uppermost 10 cm layer by 1.5–2 pH units. In the surface peat, the decomposition rate of cellulose in the ash plots was roughly double that in control plots. Annual CO2 efflux was least on the unfertilized site, 238 g CO2‐C m−2 year−1. The use of wood ash nearly doubled CO2 efflux to 420–475 g CO2‐Cm−2 year−1 on plots fertilized with 5–15 t ha−1 of ash, respectively. Furthermore, ash treatments resulted also in increased stand growth, and during the measurement year, the growing stand on ash plots accumulated carbon 11–12 times faster than the control plot. The difference between peat C emission and amount of C sequestered by trees on the ash plots was 43–58 g C m−2, while on the control plot it was 204 g C m−2. Our conclusion is that adding wood ash as a fertilizer increases more C sequestration in the tree stand than C efflux from the peat.
Temporal variability in the spatial and environmental determinants of functional metacommunity organization – stream fish in a human‐modified landscape
Authors: ERŐS T. , SÁLY P. , TAKÁCS P. , SPECZIÁR A. , BÍRÓ P.
Published: July 2012

1. Quantifying the relative importance of environmental filtering versus regional spatial structuring has become an intensively studied area in the context of metacommunity ecology. However, most studies have evaluated the role of environmental and spatial processes using taxonomic data sets of single snapshot surveys.

2. Here, we examined temporal changes in patterns and possible processes behind the functional metacommunity organization of stream fishes in a human‐modified landscape. Specifically, we (i) studied general changes in the functional composition of fish assemblages among 40 wadeable stream sites during a 3‐year study period in the catchment area of Lake Balaton, Hungary, (ii) quantified the relative importance of spatial and environmental factors as determinants of metacommunity structure and (iii) examined temporal variability in the relative role of spatial and environmental processes for this metacommunity.

3. Partial triadic analysis showed that assemblages could be effectively ordered along a functional gradient from invertebrate consuming species dominated by the opportunistic life‐history strategy, to assemblages with a diverse array of functional attributes. The analysis also revealed that functional fish assemblage structure was moderately stable among the sites between the sampling periods.

4. Despite moderate stability, variance partitioning using redundancy analyses (RDA) showed considerable temporal variability in the contribution of environmental and spatial factors to this pattern. The analyses also showed that environmental variables were, in general, more important than spatial ones in determining metacommunity structure. Of these, natural environmental variables (e.g. altitude, velocity) proved to be more influential than human‐related effects (e.g. pond area, % inhabited area above the site, nutrient enrichment), even in this landscape with relatively low variation in altitude and stream size.

5. Pond area was, however, the most important human stressor variable that was positively associated with the abundance of non‐native species with diverse functional attributes. The temporal variability in the relative importance of environmental and spatial factors was probably shaped by the release of non‐native fish from fish ponds to the stream system during flood events.

6. To conclude, both spatial processes and environmental control shape the functional metacommunity organization of stream fish assemblages in human‐modified landscapes, but their importance can vary in time. We argue, therefore, that metacommunity studies should better consider temporal variability in the ecological mechanisms (e.g. dispersal limitation, species sorting) that determine the dynamics of landscape‐level community organization.
Re‐building brown trout populations in dredged boreal forest streams: in‐stream restoration combined with stocking of young trout
Authors: LUHTA PIRKKO‐LIISA , HUUSKO ARI , LOUHI PAULIINA
Published: July 2012

1. Rivers in boreal forested areas were often dredged to facilitate the transport of timber resulting in channels with simplified bed structure and flow fields and reduced habitat suitability for stream organisms, especially lotic fishes. Currently, many streams are being restored to improve their physical habitat, by replacing boulders and gravel and removing constraining embankments. The most compelling justification behind stream restoration of former floatways has been the enhancement of native fish populations, specifically salmonids.

2. We examined the success of a stream management programme aimed at re‐building diminished brown trout (Salmo trutta) populations by monitoring densities of young‐of‐year and older trout in 18 managed and three reference streams during 2000–2005. Rehabilitation included in‐stream restoration combined with a 5‐year post‐restoration period of stocking young brown trout. Our space‐for‐time substitution design comprised four pre‐management, four under‐management, 10 post‐management and three reference streams.

3. Densities of young‐of‐year brown trout, indicating population establishment, were significantly higher in post‐ compared with pre‐management streams. However, density of young‐of‐year brown trout in post‐management streams was significantly lower compared with near‐pristine reference streams. Furthermore, success of managed brown trout population re‐building varied, indicating stream‐specific responses to management measures. Density of burbot (Lota lota), a native generalist predator, was associated with low recruitment of brown trout.

4. Stream‐specific responses imply that rehabilitation of brown trout populations cannot be precisely predicted thereby limiting application. Our findings support the importance of adaptive stream restoration and management, with focus on identifying factor(s) limiting the establishment of target fish populations.