bluuebunny/crossref_metadata_2025 huggingface dataset:
77 EFFECT OF SUGAR SUPPLEMENTATION ON THE CRYOPRESERVATION OF BOAR SPERMATOZOA
Authors: Hernandez M. , Cremades T. , Vazquez J. M. , Martinez E. A. , Roca J.
Published: January 2008

The optimization of cryopreservation extenders is an essential issue for the successful establishment of boar sperm cryobanks. The aim of the present study was to investigate the importance of sugar supplementation to the freezing extender and/or to the thawing diluents, and the interactions between these treatments on post-thaw survival of boar spermatozoa. Pooled sperm-rich fractions from 5 mature hybrid boars (5 ejaculates per boar) were divided into 7 aliquots, centrifuged at 2300g 3 min, and diluted to a final sperm concentration of approximately 1000 � 106 spermatozoa mL–1 with the freezing extender prior to freezing in 0.5-mL plastic straws; a standard freeze–thaw procedure with computer-controlled freezing equipment was utilized. All of the freezing extenders were based on Tris-citric acid buffer supplemented with 20% egg yolk and 0 mm (TC, no glucose), 0.05 mm, 2 mm, 4 mm, 10 mm, 50 mm, or 185 mm glucose (all media adjusted to 310 mOsm kg–1; pH 6.8). After thawing at 37�C/20 s, semen was immediately diluted 1:2 (v/v) with either TC (no glucose) or BTS (205 mm glucose, 20.39 mm NaCl, 5.4 mm KCl, 15 mm NaHCO3, and 3.35 mm EDTA). Post-thaw sperm motility (assessed with a computer-assisted semen analysis system) and plasma membrane and acrosome integrity (viability, assessed simultaneously by flow cytometry using triple fluorescent staining) were evaluated at 0, 30, and 150 min post-thaw and used to estimate the success of cryopreservation. Data were analyzed as a split plot design using a mixed model ANOVA including cryopreservation extender, thawing diluent, incubation time, and interactions as fixed effects and replicates as a random effect. The freezing extender did not have any significant effect on the percentage of motile or viable spermatozoa at either thawing or after 150 min (P > 0.05). There was a significant effect of incubation time (P < 0.0001) and thawing diluent (P < 0.0001) on motility and viability, with a significant interaction between them on motility (P = 0.018). Motility was similar (P > 0.05) at time 0 in both thawing diluents (mean � SEM: 49.4 � 3.7 v. 46.2 � 3.9% for BTS and TC, respectively), but decreased in Tris-diluted samples in a time-dependent manner (54.6 � 1.9 v. 42.5 � 2.6% at 30 min, and 40 � 3.4 v. 27.1 � 3.7% at 150 min). In contrast, viability was significantly higher (P < 0.05) in BTS-diluted samples at 0 (53.9 � 3.7 v. 49.7 � 3.8%), 30 (55 � 3.1 v. 47.7 � 3.31), and 150 min (51 � 4.2 v. 43.7 � 4.4%). These results indicate that, despite common beliefs, sugars are not necessary for cryopreservation but are beneficial for maintaining boar sperm metabolism for a longer time after thawing.
78 CRYOPRESERVATION OF FROG (RANA PIPIENS) SPERM CELLS COLLECTED BY NON-LETHAL METHODS
Authors: Hopkins B. K. , Herr C.
Published: January 2008

There are few reported studies of cryopreservation of frog spermatoazoa. None have used non-lethal methods for collection, which involves a simple IP injection, followed by collection of sperm from the urine. Our study compared post-thaw survival of spermatozoa frozen using three different diluents: Salamon's ram semen diluent (SSD) (Evans and Maxwell 1987 Salamon's Artificial Insemination of Sheep and Goats, Sydney, Australia: Butterworths, pp. 122–141); our modification of Salamon's diluent (MSSD), containing an additional 5.9 mL glycerol and 6.6 g of sucrose per 100 mL; and a diluent reported to be currently the most successful for freezing frog sperm: Browne's frog diluent (BFD) (Browne et al. 2002 Cryobiology 44, 251–257). The 1 � SSD was composed of 2.9 g Tris, 0.4 g glucose, 3.2 g citric acid monohydrate, 12 mL egg yolk, and 4.5 mL glycerol per 100 mL. The composition of 1 � BFD was 10 g sucrose and 15 mL DMSO per 100 mL. Ten male frogs of unknown age were injected with 200 IU hCG (Chorulon; Intravet, Millsboro, DE, USA) in 500 µL PBS. Urine specimens were collected by cloacal lavage 30, 60, and 90 min post-injection. Specimenswere stored in a cold room at 8�C until all collections were finished. Diluents requiring addition of egg yolk were completed with that from a freshly laid chicken egg. Sperm cells were pooled and concentrations were measured using microscopy. Sperm cells were divided and combined with diluents in 1.5-mL microcentrifuge tubes. Tubes were suspended in a 500-mL beaker, which was placed in an ice bath to allow slow cooling to 2�C over 45 min. Aliquots of 100 µL were pipetted into indentations on dry ice and left to freeze for 3 min. Frozen pellets were plunged into liquid N2, and while under LN2, pellets were placed in microcentrifuge tubes, which were then stuffed with cotton wool. Upon thawing, pellets were removed from LN2 and dropped into 200 µL of thawing solution (0.9085 g Tris, 0.25 g fructose, and 0.45 g citric acid per 15 mL final volume) at 21�C while gently vortexing. Spermatozoa were assessed using live/dead cell stain (Molecular Probes, Eugene, OR, USA) and fluorescent microscopy. Percentages of live spermatozoa from the three treatments were 58.5%, 70.5%, and 44.1% in SSD, MSSD, and BFD, respectively. When considering the number of sperm cells lysed along with live/dead cell stain data, 40%, 55.2%, and 34.4% in SSD, MSSD, and BFD, respectively, survived post-thaw. All values were significantly different (P < 0.001). Superior results were observed with MSSD; use of SSD also resulted in better results than BFD. The most prevalent method for collection of frog sperm is to pith the frog and then macerate the testis. With frog populations dwindling worldwide, use of a technique that is virtually harmless such as used here in conjunction with cryopreservation of specimens could be useful for preserving genetic variation in endangered frog species.
86 EFFECTS OF THREE CRYOPRESERVATION SYSTEMS ON LONGEVITY OF STALLION SPERM AFTER THAWING
Authors: Pasquini D. F. , Ferreira H. N. , Papa F. O. , Dell Aqua Jr J. A. , Alvarenga M. A.
Published: January 2008

Use of frozen semen by the horse industry is popular. Several extenders have been used to freeze stallion semen; the most used are EDTA-lactose egg yolk and INRA 82. A new extender named Botu-Crio� (BioTech, Botucatu, Sao Paulo, Brazil) has been used on a large scale in Brazil. No comparisons of these extenders have been published. The present experiment was designed to compare the ability of these three extenders to preserve sperm longevity after incubation. One ejaculate from each of 13 stallions was used. After collection using an artificial vagina, semen was filtered and diluted 1:1 with a milk-base extender (Botu-Semen�), split into 3 parts, and then centrifuged (600g/10 min). After removal of the supernatants, each semen pellet was resuspended with an aliquot of one of the extenders (INRA 82, EDTA-Lactose, or Botu-Crio) to a final concentration of 100 � 106 sperm cells mL–1. Semen was packaged in 0.5-mL French straws, and cooled for stabilization for 20 min at 5�C for Botu-Crio (BC), for 2 h at 5�C for INRA 82 (IR), and without stabilization for EDTA-Lactose (EL) extender. After stabilization, the straws were placed in nitrogen vapor for 15 min and then plunged into liquid nitrogen. Before motility evaluation by CASA using the Hamilton System Analyzer (Hamilton Thorne Biosciences, Beverly, MA, USA), straws were thawed (46�C/20 s) and then incubated at 37�C in a dry block. The patterns of total motility (TM) and progressive motility (PM) were evaluated immediately after thawing (T0), and at 10 (T10), 30 (T30), and 60 (T60) min after incubation at 37�C. Statistical analysis was performed using ANOVA and Tukey's test. Total motility, respectively, for IR, EL, and BC was TM0: 10%, 35%, and 57%; TM10: 25%, 37%, and 68%; TM30: 20%, 21%, and 56%; and TM60: 13%, 10%, and 41%. The respective progressive motility was PM0: 3%, 16%, and 28%; PM10: 11%, 16%, and 32%; PM30: 10%, 8%, and 26%; and PM60: 5%, 2%, and 16%. Motilities were always superior (P < 0.05) at all incubation times with the utilization of Botu-Crio extender. A fertility trial comparing the three extenders is in progress.
9 COMPARATIVE EFFICACY OF AN 8-DAY Cue-Mate®/ESTRADIOL BENZOATE PROGRAM WITH OR WITHOUT INCLUSION OF EQUINE CHORIONIC GONADOTROPIN IN ANESTROUS DAIRY COWS
Authors: Bryan M. A. , Emslie R. , Heuer C.
Published: January 2008

The objective was to quantify and compare the reproductive response of lactating, seasonally calving dairy cows diagnosed with anovulatory anestrus (AA) to treatment with two separate progesterone (Cue-Mate�, Bioniche Animal Health, Australasia, Armidale, NSW, Australia) and oestradiol benzoate (ODB) treatment regimes, either including or excluding eCG. Cows on six commercial seasonal-calving dairy farms in New Zealand (n = 2355) were presented following 3 weeks of tailpainting and a subsequent non-observed estrus. Cows which were confirmed in anestrus with no detectable corpus luteum (CL) by rectal palpation were selected for trial inclusion (n = 1382). All cows received the standard anestrous protocol, consisting of an 8-day insertion of the progesterone device containing 1.56 g of progesterone (Cue-Mate; injection of 2 mg of ODB at the time of insertion and further injection of 1 mg of ODB 24 h after Cue-Mate removal (Day 9)). Approximately half of the cows were randomly allocated (using the RAND function within Excel, Microsoft) to a further intervention consisting of an injection of 400 IU of eCG (Pregnecol�, Bioniche) on the day of Cue-Mate removal (Day 8). This became the Treatment group with the standard treatment the Control group. Cows were then mated to detected heats; all cows not detected in estrus and inseminated were blanket-mated 36 h after the second ODB treatment. Cows were scanned ultrasonically 10 weeks post-treatment and all pregnancies were aged to the nearest half-week. Where two matings were recorded within 7 days of each other, the later mating was used. Data were analyzed using both a matched logistic regression analysis and survival analysis, using SPSS (SPSS.com) and SAS (SAS.com). Pregnecol-treated cows were more likely to conceive in the first 48 h following treatment (48.84% v. 43.10%; P = 0.06), and were more likely to be in calf within 7 days following treatment (P = 0.07). The effect of Pregnecol was greater in cows over 5 years of age, such that this stratum of cows was significantly more likely to conceive within 48 h [58.33% v. 38.10%; P = 0.00; adjusted relative risk (RR) 1.51; 95% lower confidence interval (LCI) 1.15; 95% upper confidence interval (UCI) 2.00], and was significantly more likely to be in calf within 7 days (55.20% v. 37.86%; P = 0.00; RR 1.44; LCI 1.41; UCI 1.82). Pregnecol-treated cows over 5 years of age were significantly more likely to be in calf at 4 weeks (72.22% v. 59.57%; P = 0.02; RR 1.21; LCI 1.03; UCI 1.42). Cows that had calved less than 50 days were significantly less likely to be in calf by 4 weeks (62.26% v. 69.35%; P = 0.04). In summary, the addition of a 400 IU treatment of eCG (Pregnecol) at the time of Cue-Mate removal in a standard 8-day progesterone device/ODB anestrous treatment program increased the risk of pregnancy. The effects of eCG on cows over 5 years of age were very strong and highly significant.
The Rho5 GTPase is necessary for oxidant-induced cell death in budding yeast
Authors: Singh Komudi , Kang Pil Jung , Park Hay-Oak
Published: January 2008

In both animal and yeast cells, reactive oxygen species (ROS) are produced as byproducts of metabolism and upon exposure to diverse environmental stresses. Cellular defense systems operate to avoid molecular damage caused by ROS, but the redox balance is disturbed under excessive stress. Cells of the budding yeast
Saccharomyces cerevisiae
undergo apoptotic-like cell death upon exposure to hydrogen peroxide (H
2
O
2
). Here, we report that the Rho5 GTPase of budding yeast is necessary for H
2
O
2
-induced cell death, which accompanies ROS accumulation and DNA fragmentation. Unlike WT, a
rho5
deletion mutant (
rho5
Δ) exhibits little cell death, whereas the constitutively active
rho5
G12V
mutant exhibits excess ROS accumulation and increased cell death upon H
2
O
2
treatment. Consistent with a role in the oxidative stress response, Rho5 interacts with the thioredoxin reductase Trr1, a key component of the cytoplasmic thioredoxin antioxidant system, in a GTP-dependent manner. This interaction occurs on the vacuolar membrane before exposure to H
2
O
2
but also in the vacuolar lumen after H
2
O
2
treatment. Trr1 levels are elevated in
rho5
Δ cells but are elevated only slightly in WT and not in the
rho5
G12V
cells after H
2
O
2
treatment. Taken together, these data suggest that Rho5 mediates H
2
O
2
-induced cell death by regulating the level of Trr1 or by excluding Trr1 from its cytoplasmic substrate.
Lessons from the past: Familial aggregation analysis of fatal pandemic influenza (Spanish flu) in Iceland in 1918
Authors: Gottfredsson Magnús , Halldórsson Bjarni V. , Jónsson Stefán , Kristjánsson Már , Kristjánsson Kristleifur , Kristinsson Karl G. , Löve Arthur , Blöndal Thorsteinn , Viboud Cécile , Thorvaldsson Sverrir , Helgason Agnar , Gulcher Jeffrey R. , Stefánsson Kári , Jónsdóttir Ingileif
Published: January 2008

The pandemic influenza of 1918 (Spanish flu) killed 21–50 million people globally, including in Iceland, where the characteristics and spread of the epidemic were well documented. It has been postulated that genetic host factors may have contributed to this high mortality. We identified 455 individuals who died of the Spanish flu in Iceland during a 6-week period during the winter of 1918, representing >92% of all fatal domestic cases mentioned by historical accounts. The highest case fatality proportion was 2.8%, and peak excess mortality was 162/100,000/week. Fatality proportions were highest among infants, young adults, and the elderly. A genealogical database was used to study relatedness and relative risk (RR) of the fatal influenza victims and relatives of their unaffected mates. The significance of these RR computations was assessed by drawing samples randomly from the genealogical database matched for age, sex, and geographical distribution. Familial aggregation of fatalities was seen, with RRs for death ranging from 3.75 for first-degree relatives (
P
< 0.0001) to 1.82 (
P
= 0.005), 1.12 (
P
= 0.252), and 1.47 (
P
= 0.0001) for second- to fourth-degree relatives of fatal influenza victims, respectively. The RRs within the families of unaffected mates of fatal influenza victims were 2.95 (
P
< 0.0001), 1.27 (
P
= 0.267), 1.35 (
P
= 0.04), and 1.42 (
P
= 0.001), for first- to fourth-degree relatives, respectively. In conclusion, the risk of death from the Spanish flu was similar within families of patients who succumbed to the illness and within families of their mates who survived. Our data do not provide conclusive evidence for the role of genetic factors in susceptibility to the Spanish flu.
Risk Factors for Suicide Attempts in Methamphetamine‐Dependent Patients
Authors: Glasner‐Edwards Suzette , Mooney Larissa J. , Marinelli‐Casey Patricia , Hillhouse Maureen , Ang Alfonso , Rawson Richard ,   the Methamphetamine Treatment Project Corporate Authors
Published: January 2008

The purpose of this study was to identify risk factors for suicide attempts (SA) in methamphetamine (MA)‐dependent patients. MA‐dependent adults (N = 526) who participated in the Methamphetamine Treatment Project were interviewed before and three years after treatment. Baseline psychiatric, medical, demographic, and substance use characteristics were assessed using the Addiction Severity Index and the Beck Depression Inventory (BDI). Lifetime history of SA was assessed at follow‐up. Risk factors for SA included gender, intravenous MA use, BDI > 20 at baseline, and clinically significant psychiatric history. Psychiatric characteristics of MA users are strongly associated with SA, warranting careful assessment of psychiatric history.
Acamprosate Efficacy in Alcohol‐Dependent Patients: Summary of Results from Three Pivotal Trials
Authors: Kranzler Henry R. , Gage Allyson
Published: January 2008

In 2004, the United States Food and Drug Administration (FDA) approved acamprosate for use in conjunction with psychosocial support in the maintenance of abstinence in alcohol‐dependent patients who are abstinent at treatment initiation. That approval was based primarily on a re‐analysis of three European double‐blind, placebo‐controlled trials in which complete abstinence was the primary outcome measure. The current report presents data from the re‐analysis of the pivotal trials, which were 13‐, 48‐, and 52‐week studies. A total of 998 DSM‐III‐R alcohol‐dependent patients were included in the studies, with the majority abstinent at randomization. Using a more stringent definition of abstinence, re‐analysis of the rate of complete abstinence, percent days abstinent, and the time to first drink confirmed the original findings for the efficacy of acamprosate in the treatment of alcohol dependence. Rate of complete abstinence was significantly higher with acamprosate than placebo (p < .05); both percent days abstinent and time to first drink were also significantly greater among acamprosate‐treated than placebo‐treated patients (p < .01). These findings support the use of acamprosate in the treatment of alcohol dependence and illustrate some of the issues that can arise in the FDA process for approval of medications to treat the disorder.
The ‘Northern Dominator’ and the Mare Nostrum: Fascist Italy's ‘Cultural War’ in Malta
Authors: Baldoli Claudia
Published: January 2008

Within the wider attempt to transform Italian communities abroad into Fascist colonies, the Italian Fasci Abroad sought to build nationalist propaganda in the Mediterranean. The irredentist activities and the propaganda of the Fasci in Malta alarmed the British governors on the island, the British government and MI5. This article analyses the cultural conflict organised in Maltese schools, bookshops and universities by the Italian nationalists against the British protectorate–a conflict the British suspected could be followed by military activity, in particular when Italy began building its empire in Ethiopia. The nationalist offensive was supported in the 1920s and, more vigorously, in the 1930s by the Fasci, the Italian consulate on the island and, ultimately, the Italian government. Not even the Second World War and the bombing of Malta by the Italian air force concluded the conflict between Italian and British imperialism on the island.
Anti-Zionism and the Italian Extreme Right
Authors: Chiarini Roberto
Published: January 2008

There are few issues that better illustrate the unresolved condition of the Italian right in the postwar period (neo-fascist in identity, democratic from necessity) than that of its stance on Israel, the Jews and Zionism. In the aftermath of the fall of fascism, the right had no difficulty in combining the defence of anti-Jewishness with domestic anti-anti-fascist policies and a foreign policy that was hostile towards the ‘allies’ of 1940–1945. Yet as soon as political competition became oriented around pro- and anti-communism, the right was, over time, driven to play down the recollections of fascism and specifically its antipathy towards Israel, not to mention its anti-Zionism. The exacerbation of the Middle East problem and the right's foreign policy response to it led to a further evolution in its stance, eventually culminating in a definitive end to any ambivalence on the issue with the birth of the ‘National Alliance’. From that point onwards, anti-Zionism found support only in the utterances of neo-Nazi skinheads and the banners of rowdy fans at the ‘northern end’ of football stadia.
Kinetic estimate of the shielding of resonant magnetic field perturbations by the plasma in DIII-D
Authors: Heyn Martin F. , Ivanov Ivan B. , Kasilov Sergei V. , Kernbichler Winfried , Joseph Ilon , Moyer Richard A. , Runov Alexey M.
Published: January 2008

Effects of linear plasma response currents on non-axisymmetric magnetic field perturbations from the I-coil used for edge localized mode mitigation in DIII-D tokamak are analysed with the help of a kinetic plasma response model developed for cylindrical geometry. It is shown that these currents eliminate the ergodization of the magnetic field in the core plasma and reduce the size of the ergodic layer at the edge. A simple balance model is proposed which qualitatively reproduces the evolution of the plasma parameters in the pedestal region with the onset of the perturbation. It is suggested that the experimentally observed density pump-out effect in the long mean free path regime is the result of a combined action of ion orbit losses and magnetic field ergodization at the edge.
MD Simulation of Effect of Crystal Orientation and Cutting Direction on Nanometric Cutting Using AFM Pin Tool
Authors: Zhang Jun-jie , Sun Tao , Yan Yong-da , Liang Ying-chun , Dong Shen
Published: January 2008

Three-dimensional molecular dynamics simulations of nanometric cutting monocrystalline copper using atomic force microscopy pin tool are conducted to investigate the effect of crystal orientation and corresponding cutting direction on the deformation characteristics. EAM potential and Morse potential are utilized respectively to compute the interactions between workpiece atoms, interactions between workpiece atoms and tool atoms. The results reveal that the nanometric cutting processes are significantly affected by crystal orientation and cutting direction. Along the [110] cutting direction, better quality of chip pattern and smaller workpiece material deformation region can be obtained than along the [100] cutting direction. Cutting the workpiece material (110) crystal orientation, samaller chip volume and smaller subsurface deformed region can be obtained than cutting the workpiece material (100) crystal orientation. The variations of workpiece atoms potential energy in different cutting processes are investigated.
Controlled Synthesis of Se/Te Alloy and Te Nanowires
Authors: Qin Dong-huan , Tao Hong , Cao Yong
Published: January 2008

Se/Te alloy and Te nanowires (NWs) with different morphologies were synthesized through a novel, controllable solution-phase method. Sodium dodecylbenzene sulfonate was employed as a surfactant to control the reaction rate in the synthesis. Through reaction process dynamics control, both "bending" and "V-shaped" Se/Te alloy NWs were controllably produced. The phase structures and morphologies of the Se/Te and Te products were investigated with XRD, TEM, and HRTEM. The formation mechanisms of the NWs were investigated on the basis of the experimental results. The significance of these results lies in the important implications concerning the potential use of these NWs materials for nanoscale electronic devices.
Molecular Orientation and Structure in LB Films of a Liquid Crystal MPUOPM Investigated by UV-Vis and IR Spectroscopy
Authors: Cheng Yu-chuan , Zhao Bing , Wang Xu , Xu Wei-qing
Published: January 2008

Langmuir monolayers and LB films of 4-((s)-2-methylbutoxy)phenyl-(4-(10-undecen-1-oyloxy)phenyl) methylenimine (MPUOPM) were investigated by ultraviolet-visible, polarized infrared spectroscopy. -A isotherms showed well-defined Langmuir monolayers were formed at an air/water interface for the MPUOPM and their mixture with SA. An inflection point at 13 mN/m appeared on the isotherm, which was due to the transition from the monolayer to multilayer. The polarized IR spectra of LB films of MPUOPM had provided new insight into the molecular orientation and structure. In LB films, the tilted angle between the alkyl chain and the normal line of the substrate was 48, the tilted angle between the dipole moment of C=N and the normal line of the substrate was 51. The alkyl chains assumed a trans-zigzag conformation but it included a few gauche conformers. The C=N groups were almost in one plane in the LB films.
Characterization and Catalytic Behavior of Nano Pt/MgO Catalysts
Authors: Yang Min , Papp Helmut
Published: January 2008

Pt/MgO catalysts were prepared by using wet impregnation method. X-ray diffraction, transmission electron microcopy (TEM), electron spectroscopy for chemical analysis, and temperature programmed surface reaction (TPSR) were used to characterize the calcined and used catalysts. Partial Oxidation of Methane (POM) to synthesis gas was carried out in a fixed bed micro-reactor to test the catalytic activity. TEM images revealed that Pt particles have the size of less than 10 nm, the size of the support MgO is about 50200 nm. At 800C, the Pt/MgO catalyst exhibited a very high activity and stability for POM reaction. Both the conversion of methane and selectivities to CO and H2 remained almost constant up to 120 h. The dispersed Pt existed in the metallic state. The state and the dispersion of active Pt and the structure of support MgO were very stable, together with the high ability to resist carbon deposition, made the catalysts show a very high stability for POM under stoichiometric reaction conditions.
Facile Route Using Highly Arrayed PMMA Spheres as Hard Template for the Fabrication of 3D Ordered Nanoporous MgO
Authors: Li Hui-ning , Dai Hong-xing , He Hong , Tong Au Chak
Published: January 2008

Using magnesium nitrate as Mg source and regularly packed polymethyl methacrylate (PMMA) spheres were synthesized via a combined strategy of emulsifier-free emulsion polymerization and water floating technique as hard template, we fabricated ordered nanoporous magnesium oxide. The synthesized PMMA and MgO samples were characterized by N2 adsorption-desorption, X-ray diffraction, high-resolution scanning electron microscopy, transmission electron microscopy, and selected area electron diffraction. It was observed that the synthesized PMMA spheres possessed a uniform diameter of approximately 284 nm and were in a highly ordered array, and the MgO generated by using the PMMA-templating method exhibited polycrystallinity with three-dimensionally ordered pores. BET surface area of the synthesized MgO sample is 100.7 m2/g, pore volume is 0.46 cm3/g, wall thickness is 424 nm, and pore sizes are in the range of 10120 nm. Such a 3D high-surface-area nanoporous strongly basic MgO is useful in the applications of catalyst supports and acidic gas adsorbents.
Preparation and Refractive Index of Nano BST Thin Films
Authors: Li Song-zhan , Yang Yan-qin , Liu Wen-cong , Zhang Tian-jin , Qi Ya-jun
Published: January 2008

Radio frequency magnetron sputtering technique is used to deposit Ba0.65Sr0.35TiO3 (BST) thin films on fused quartz substrates. In order to prepare the high quality BST thin films, the crystallization and mi-crostructure of the films were characterized by X-ray diffraction, field emission scanning electron microscopy and atom force microstructure. The more intense characteristic diffraction peaks and better crystallization can be observed in BST thin films deposited at 600C and subsequently annealed at 700C. The refractive index of the films is determined from the measured transmission spectra. The dependences of the refractive index on the deposition parameters of BST thin films are different. The refractive index of the films increases with the substrate temperature. At lower sputtering pressure, the refractive index increases from 1.797 to 2.179 with the pressure increase. However, when the pressure increases up to 3.9 Pa, the refractive index instead reduces to 1.860. The oxygen to argon ratio also plays an important effect on the refractive index of the films. It has been found that the refractive index increases with the ratio of oxygen to argon increasing. The refractive index of BST thin films is strongly dependent on the annealing temperature, which also increases as the annealing temperature ascends. In one word, the refractive index of BST thin films is finally affected by the films microstructure and texture.
Synthesis and Tribological Properties of Tubular NbS2 and TaS2 Nanostructures
Authors: Liu Yan-qing , Li Chang-sheng , Yang Jing-hai , Yu Yun-ming , Li Xiao-kui
Published: January 2008

NbS2 and TaS2 nanostubes were prepared via solid state reaction method, and their tribological properties were studied over a wide range of normal loads and sliding velocities. The size distributions and shapes of sulfides were characterized using transmission electron microscopy and scanning electron microscopy. The results indicated that the NbS2 and TaS2 compounds had tubular structures with the mean diameter of 100 nm and length of 10 mm. The effect of NbS2 and TaS2 nanotubes added in commercial lubricating oil T40, was initially studied using the instrument MS-T3000. The results showed that the antiwear ability of NbS2 and TaS2 as additives was obviously better than that of the normal lubricating oil in ambient conditions. The general frictional properties of the solid lubricant containing TaS2 is better than those of the solid lubricant containing NbS2. The frictional mechanism was discussed.
Fluorescent Property of Gold Nanoparticles with Different Surface Structures
Authors: Zhang Zhi-juan , Wang Chun-xia , Wang Yong , Niu Shu-hua , Lu Chang-gui , Fu De-gang
Published: January 2008

Fluorescence spectra of naked gold nanoparticles, triphenylphosphine stabled gold nanoparticles, and 3-mercaptopropionic acid substituted gold nanoparticles were studied. It was found that fluorescence intensities of gold nanoparticles were highly sensitive to surface molecules. The fluorescence quenching effect of these gold nanoparticles on CdSe nanoparticles was also investigated. This quenching effect was related to the overlap degree between the absorption spectra of gold nanoparticles and the emission spectrum of CdSe nanoparticles, and was surface-dependent as well.
Global Analysis of Yeast Endosomal Transport Identifies the Vps55/68 Sorting Complex
Authors: Schluter Cayetana , Lam Karen K.Y. , Brumm Jochen , Wu Bella W. , Saunders Matthew , Stevens Tom H. , Bryan Jennifer , Conibear Elizabeth
Published: January 2008

Endosomal transport is critical for cellular processes ranging from receptor down-regulation and retroviral budding to the immune response. A full understanding of endosome sorting requires a comprehensive picture of the multiprotein complexes that orchestrate vesicle formation and fusion. Here, we use unsupervised, large-scale phenotypic analysis and a novel computational approach for the global identification of endosomal transport factors. This technique effectively identifies components of known and novel protein assemblies. We report the characterization of a previously undescribed endosome sorting complex that contains two well-conserved proteins with four predicted membrane-spanning domains. Vps55p and Vps68p form a complex that acts with or downstream of ESCRT function to regulate endosomal trafficking. Loss of Vps68p disrupts recycling to the TGN as well as onward trafficking to the vacuole without preventing the formation of lumenal vesicles within the MVB. Our results suggest the Vps55/68 complex mediates a novel, conserved step in the endosomal maturation process.
Acupuncture Effects on Cardiac Functions Measured by Cardiac Magnetic Resonance Imaging in a Feline Model
Authors: Lin Jen-Hsou , Shih Chen-Haw , Kaphle Krishna , Wu Leang-Shin , Tseng Weng-Yih , Chiu Jen-Hwey , Lee Tzu-chi , Wu Ying-Ling
Published: January 2008

The usefulness of acupuncture (AP) as a complementary and/or alternative therapy in animals is well established but more research is needed on its clinical efficacy relative to conventional therapy, and on the underlying mechanisms of the effects of AP. Cardiac magnetic resonance imaging (CMRI), an important tool in monitoring cardiovascular diseases, provides a reliable method to monitor the effects of AP on the cardiovascular system. This controlled experiment monitored the effect electro‐acupuncture (EA) at bilateral acupoint Neiguan (PC6) on recovery time after ketamine/xylazine cocktail anesthesia in healthy cats. The CMRI data established the basic feline cardiac function index (CFI), including cardiac output and major vessel velocity. To evaluate the effect of EA on the functions of the autonomic nervous and cardiovascular systems, heart rate, respiration rate, electrocardiogram and pulse rate were also measured. Ketamine/xylazine cocktail anesthesia caused a transient hypertension in the cats; EA inhibited this anesthetic‐induced hypertension and shortened the post‐anesthesia recovery time. Our data support existing knowledge on the cardiovascular benefits of EA at PC6, and also provide strong evidence for the combination of anesthesia and EA to shorten post‐anesthesia recovery time and counter the negative effects of anesthetics on cardiac physiology.
Heterospecific harassment of native endangered fishes by invasive guppies in Mexico
Authors: Valero Alejandra , Macías Garcia Constantino , Magurran Anne E
Published: January 2008

Persistent courtship by male Trinidadian guppies (
Poecilia reticulata
) is costly for conspecific females. Since male guppies are known to attempt matings with other poeciliid females, we asked whether persistent courtship is also directed towards morphologically similar but phylogenetically distant females encountered following invasion.
Skiffia bilineata
is one of several endangered viviparous goodeids from Central México, whose remaining habitats are increasingly shared with invasive guppies. Experiments in which guppy sex ratios were manipulated to vary the proportion of heterospecific to conspecific females showed that male guppies courted and attempted forced copulations with
S. bilineata
females even when females of their own species were in excess. This behaviour places an additional, and previously unrecognized, burden on a group of endemic Mexican fishes already in risk of extinction.
Free radicals run in lizard families
Authors: Olsson Mats , Wilson Mark , Uller Tobias , Mott Beth , Isaksson Caroline , Healey Mo , Wanger Thomas
Published: January 2008

In the ageing individual, the production of reactive oxygen species (ROS) accelerates with cell senescence. Depending on the heritability of the underlying processes that determine net ROS levels, this may influence ageing
per se
and its evolutionary direction and rate of change. In order to understand the inheritance and evolution of net ROS levels in free-ranging lizards, we used flow cytometry together with ROS-sensitive fluorogenic probes to measure ROS in lizard blood cells. We measured basal levels of (i) non-specific ROS (superoxide, singlet oxygen, H
2
O
2
and peroxynitrite), (ii) superoxide specifically and (iii) superoxide after CCCP treatment, which elevated ROS production in the mitochondria. The cumulative level of non-specific ROS was higher in adults than juveniles and superoxide level showed high heritability and variability among families. We suggest that the evolution of ROS dynamics may be ROS species specific and perhaps depend on the relative degree of uni- or biparental inheritance of ROS main regulatory pathways.
Periodic travelling waves in cyclic populations: field studies and reaction–diffusion models
Authors: Sherratt Jonathan A , Smith Matthew J
Published: January 2008

Periodic travelling waves have been reported in a number of recent spatio-temporal field studies of populations undergoing multi-year cycles. Mathematical modelling has a major role to play in understanding these results and informing future empirical studies. We review the relevant field data and summarize the statistical methods used to detect periodic waves. We then discuss the mathematical theory of periodic travelling waves in oscillatory reaction–diffusion equations. We describe the notion of a wave family, and various ecologically relevant scenarios in which periodic travelling waves occur. We also discuss wave stability, including recent computational developments. Although we focus on oscillatory reaction–diffusion equations, a brief discussion of other types of model in which periodic travelling waves have been demonstrated is also included. We end by proposing 10 research challenges in this area, five mathematical and five empirical.
Robustness of linkage maps in natural populations: a simulation study
Authors: Slate Jon
Published: January 2008

In a number of long-term individual-based studies of vertebrate populations, the genealogical relationships between individuals have been established with molecular markers. As a result, it is possible to construct genetic linkage maps of these study populations by examining the co-segregation of markers through the pedigree. There are now four free-living vertebrate study populations for whom linkage maps have been built. In this study, simulation was used to investigate whether these linkage maps are likely to be accurate. In all four populations, the probability of assigning markers to the correct chromosome is high and framework maps are generally inferred correctly. However, genotyping error can result in incorrect maps being built with very strong statistical support over the correct order. Future applications of linkage maps of natural populations are discussed.
Nonlinear Analysis of a Thin Circular Functionally Graded Plate and Large Deflection Effects on the Forces and Moments
Authors: Allahverdizadeh A. , Rastgo A. , Naei M. H.
Published: January 2008

Nonlinear analysis of a thin circular functionally grade plate is formulated in terms of von Karman’s dynamic equations. The plate thickness is constant and temperature-dependent functionally graded material (FGM) properties vary through the thickness of the plate. Forces and moments of the plate, due to large vibration amplitudes, are developed in this paper by solving the governing equations for harmonic vibrations. Corresponding results are illustrated in the case of steady-state free vibration. The results show that the variation of volume fraction index is influential in forces, moments, and FGM properties.
Constitutive Behavior and Temperature Effects in NR and SBR Under Variable Amplitude and Multiaxial Loading Conditions
Authors: Harbour Ryan J. , Fatemi Ali , Mars Will V.
Published: January 2008

Knowledge of the stress response of a material to the applied deformations is necessary for many engineering analysis and applications. This paper addresses the observed effects of load sequencing, Mullins effect, and multiaxial loading on the constitutive behavior of rubber under variable amplitude conditions for a series of experiments using multiaxial ring test specimens. Two filled rubber materials were used and compared in this study; natural rubber, which strain crystallizes, and styrene butadiene rubber (SBR), which does not. A pseudoelastic approach is used to model the cyclic stress-strain response for both materials. The implications of inelasticity when using hyperelastic material models are also discussed. Based on temperature results for the multiaxial ring specimen obtained via a thermal imaging system for SBR, a model capable of accurately predicting surface temperature for the multiaxial ring specimen as a function of hysteresis area and test frequency has been developed.
Modeling of the Rate Responsive Behavior of Elastomer Foam Materials
Authors: Pan Feixia
Published: January 2008

Elastomer foam materials are shock absorbers that have been extensively used in applications of electronic packaging. Finite element modeling simulation plays an important role in helping the designers determine the best elastomer foam material and the best structure of a shock absorber. Elastomer foam materials have very complicated material behaviors. The prediction of the rate responsive behavior is one of the most interesting topics in elastomer material modeling. The focus of this article is to present a unique method for deriving the rate dependent constitutive model of an elastomer foam based on the extension of the Cowper and Symond law and the curve fitting on experimental test data. The research on rate dependent material models and the material models available in commercially available finite element analysis software have been reviewed. Test data collection at various strain rates has been discussed. Two steps of curve fitting on experimental test data are used to retrieve analytical expression of the constitutive model. The performance of the constitutive model for a foam material has been illustrated and shown to be quite good. This method is easy to understand and the simple formulation of the constitutive model is very suitable for applications in numerical simulation. The constitutive model could be used to predict the stress-strain curves of a foam material at any strain rate, especially at the intermediate strain rates, which are the most difficult to collect so far. In addition, this model could be readily integrated with the hyperelastic material models to more efficiently evaluate the mechanical behavior of an elastomer foam material. The model could potentially be implemented in commercially available software such as ABAQUS and LS-DYNA. The method presented is also useful in deriving constitutive models of rubberlike elastomer materials.
Control of Genic DNA Methylation by a jmjC Domain-Containing Protein in
Arabidopsis thaliana
Authors: Saze Hidetoshi , Shiraishi Akiko , Miura Asuka , Kakutani Tetsuji
Published: January 2008

Differential cytosine methylation of repeats and genes is important for coordination of genome stability and proper gene expression. Through genetic screen of mutants showing ectopic cytosine methylation in a genic region, we identified a jmjC-domain gene,
IBM1 (increase in bonsai methylation 1
), in
Arabidopsis thaliana
. In addition to the ectopic cytosine methylation, the
ibm1
mutations induced a variety of developmental phenotypes, which depend on methylation of histone H3 at lysine 9. Paradoxically, the developmental phenotypes of the
ibm1
were enhanced by the mutation in the chromatin-remodeling gene
DDM1
(
decrease in DNA methylation 1
), which is necessary for keeping methylation and silencing of repeated heterochromatin loci. Our results demonstrate the importance of chromatin remodeling and histone modifications in the differential epigenetic control of repeats and genes.
Vaccine To Confer to Nonhuman Primates Complete Protection against Multistrain Ebola and Marburg Virus Infections
Authors: Swenson Dana L. , Wang Danher , Luo Min , Warfield Kelly L. , Woraratanadharm Jan , Holman David H. , Dong John Y. , Pratt William D.
Published: January 2008

Filoviruses (Ebola and Marburg viruses) are among the deadliest viruses known to mankind, with mortality rates nearing 90%. These pathogens are highly infectious through contact with infected body fluids and can be easily aerosolized. Additionally, there are currently no licensed vaccines available to prevent filovirus outbreaks. Their high mortality rates and infectious capabilities when aerosolized and the lack of licensed vaccines available to prevent such infectious make Ebola and Marburg viruses serious bioterrorism threats, placing them both on the category A list of bioterrorism agents. Here we describe a panfilovirus vaccine based on a complex adenovirus (CAdVax) technology that expresses multiple antigens from five different filoviruses de novo. Vaccination of nonhuman primates demonstrated 100% protection against infection by two species of Ebola virus and three Marburg virus subtypes, each administered at 1,000 times the lethal dose. This study indicates the feasibility of vaccination against all current filovirus threats in the event of natural hemorrhagic fever outbreak or biological attack.
NPXY Motifs in the β1 Integrin Cytoplasmic Tail Are Required for Functional Reovirus Entry
Authors: Maginnis Melissa S. , Mainou Bernardo A. , Derdowski Aaron , Johnson Elizabeth M. , Zent Roy , Dermody Terence S.
Published: January 2008

Reovirus cell entry is mediated by attachment to cell surface carbohydrate and junctional adhesion molecule A (JAM-A) and internalization by β1 integrin. The β1 integrin cytoplasmic tail contains two NPXY motifs, which function in recruitment of adaptor proteins and clathrin for endocytosis and serve as sorting signals for internalized cargo. As reovirus infection requires disassembly in the endocytic compartment, we investigated the role of the β1 integrin NPXY motifs in reovirus internalization. In comparison to wild-type cells (β1+/+ cells), reovirus infectivity was significantly reduced in cells expressing mutant β1 integrin in which the NPXY motifs were altered to NPXF (β1+/+Y783F/Y795F cells). However, reovirus displayed equivalent binding and internalization levels following adsorption to β1+/+ cells and β1+/+Y783F/Y795F cells, suggesting that the NPXY motifs are essential for transport of reovirus within the endocytic pathway. Reovirus entry into β1+/+ cells was blocked by chlorpromazine, an inhibitor of clathrin-mediated endocytosis, while entry into β1+/+Y783F/Y795F cells was unaffected. Furthermore, virus was distributed to morphologically distinct endocytic organelles in β1+/+ and β1+/+Y783F/Y795F cells, providing further evidence that the β1 integrin NPXY motifs mediate sorting of reovirus in the endocytic pathway. Thus, NPXY motifs in the β1 integrin cytoplasmic tail are required for functional reovirus entry, which indicates a key role for these sequences in endocytosis of a pathogenic virus.
The Fusion Protein of Respiratory Syncytial Virus Triggers p53-Dependent Apoptosis
Authors: Eckardt-Michel Julia , Lorek Markus , Baxmann Diane , Grunwald Thomas , Keil Günther M. , Zimmer Gert
Published: January 2008

Infection with respiratory syncytial virus (RSV) frequently causes inflammation and obstruction of the small airways, leading to severe pulmonary disease in infants. We show here that the RSV fusion (F) protein, an integral membrane protein of the viral envelope, is a strong elicitor of apoptosis. Inducible expression of F protein in polarized epithelial cells triggered caspase-dependent cell death, resulting in rigorous extrusion of apoptotic cells from the cell monolayer and transient loss of epithelial integrity. A monoclonal antibody directed against F protein inhibited apoptosis and was also effective if administered to A549 lung epithelial cells postinfection. F protein expression in epithelial cells caused phosphorylation of tumor suppressor p53 at serine 15, activation of p53 transcriptional activity, and conformational activation of proapoptotic Bax. Stable expression of dominant-negative p53 or p53 knockdown by RNA interference inhibited the apoptosis of RSV-infected A549 cells. HEp-2 tumor cells with low levels of p53 were not sensitive to RSV-triggered apoptosis. We propose a new model of RSV disease with the F protein as an initiator of epithelial cell shedding, airway obstruction, secondary necrosis, and consequent inflammation. This makes the RSV F protein a key target for the development of effective postinfection therapies.
Early Phosphatidylinositol 3-Kinase/Akt Pathway Activation Limits Poliovirus-Induced JNK-Mediated Cell Death
Authors: Autret Arnaud , Martin-Latil Sandra , Brisac Cynthia , Mousson Laurence , Colbère-Garapin Florence , Blondel Bruno
Published: January 2008

Poliovirus (PV)-induced apoptosis seems to play a major role in tissue injury in the central nervous system (CNS). We have previously shown that this process involves PV-induced Bax-dependent mitochondrial dysfunction mediated by early JNK activation in IMR5 neuroblastoma cells. We showed here that PV simultaneously activates the phosphatidylinositol 3-kinase (PI3K)/Akt survival signaling pathway in these cells, limiting the extent of JNK activation and thereby cell death. JNK inhibition is associated with PI3K-dependent negative regulation of the apoptosis signal-regulating kinase 1, which acts upstream from JNK in PV-infected IMR5 cells. In poliomyelitis, this survival pathway may limit the spread of PV-induced damage in the CNS.