The radio-frequency single-electron transistor (RF-SET): A fast and ultrasensitive electrometer

A new type of electrometer is described that uses a single-electron transistor (SET) and that allows large operating speeds and extremely high charge sensitivity. The SET readout was accomplished by measuring the damping of a 1.7-gigahertz resonant circuit in which the device is embedded, and in some ways is the electrostatic "dual" of the well-known radio-frequency superconducting quantum interference device. The device is more than two orders of magnitude faster than previous single-electron devices, with a constant gain from dc to greater than 100 megahertz. For a still-unoptimized device, a charge sensitivity of 1.2 x 10(-5) e/hertz was obtained at a frequency of 1.1 megahertz, which is about an order of magnitude better than a typical, 1/f-noise-limited SET, and corresponds to an energy sensitivity (in joules per hertz) of about 41 Planck's over 2pi.     

Alpha‐Linolenic Acid Supplementation in Tris Extender Can Improve Frozen–Thawed Bull Semen Quality

The study was conducted to evaluate the effects of α ‐linolenic acid (ALA) on frozen–thawed quality and fatty acid composition of bull sperm. For that, twenty‐four ejaculates obtained from three bulls were diluted in a Tris extender containing 0 (control), 3, 5, 10 and 15 ng/ml of ALA. Extended semen was incubated at 37°C for 15 min, to allow absorption of ALA by sperm cell membrane. The sample was chilled for 2 h, packed into 0.25‐ml straws and frozen in liquid nitrogen for 24 h. Subsequently, straws were thawed and evaluated for total sperm motility (computer‐assisted semen analysis), membrane functional integrity (hypo‐osmotic swelling test), viability (eosin‐nigrosin), fatty acid composition (gas chromatography) and lipid peroxidation (thiobarbituric acid‐reactive substances (TBARS)). A higher (p < 0.05) percentage of total sperm motility was observed in ALA groups 5 ng/ml (47.74 ± 07) and 10 ng/ml (44.90 ± 0.7) in comparison with control (34.53 ± 3.0), 3 ng/ml (34.40 ± 2.6) and 15 ng/ml (34.60 ± 2.9). Still, the 5 ng/ml ALA group presented a higher (p < 0.05) percentage of viable sperms (74.13 ± 0.8) and sperms with intact membrane (74.46 ± 09) than all other experimental groups. ALA concentration and lipid peroxidation in post‐thawed sperm was higher in all treated groups when compared to the control group. As such, the addition of 5 ng/ml of ALA to Tris extender improved quality of frozen–thawed bull spermatozoa.     

Free radical oxidation products in plasma and synovial fluid of horses with synovial inflammation

SUMMARY: Free radical oxidation products, namely conjugated dienes, ultraviolet fluorescence (excitation 325 nm, emission 395 nm) and visible fluorescence (excitation 360 nm, emission 460 nm) were measured in equine synovial fluid exposed to free radicals In vitro and in the plasma and synovial fluids of horses with synovial effusions. The synovial effusions were induced by intra-articularly administered carrageenin (0.3 ml, 1%), which rarely resulted in clinical lameness. The free radicals were generated In vitro by mixtures of iron and ethylene diamine tetra acetate (Fe/EDTA) or mixtures of hypoxanthine and xanthine oxidase (HX/XO). The conjugated diene concentrations and intensity of ultraviolet fluorescence were negligible in plasma and synovial fluid specimens. No increase resulted from incubation of synovial fluids with either a free radical generating system or as a result of the induced inflammation. The intensity of visible fluorescence did not increase in specimens incubated with Fe/EDTA. However, the intensity of visible fluorescence increased in specimens incubated with HX/XO, in synovial effusions induced by carrageenin, in plasma and in synovial fluids aspirated from saline injected controls. The results indicate that the intensity of visible fluorescence of equine synovial fluid increases after exposure to free radicals and during synovitis in the horse, suggesting a possible role for free radicals in the pathogenesis of equine inflammatory joint diseas     

Ostertagiasis in calves. II. infection parameters and body weight gains following housing

The performance of six groups of six calves each from a previous field experiment was followed from the beginning of housing until turning out seven months later. When housed the groups harboured different levels of infection with Ostertagia ostertagi and had corresponding weight and gain reductions. The most heavily infected groups improved rapidly following housing. Elevated serum pepsinogen levels decreased markedly, and approached normal values at eight weeks. Differences in serum pepsinogen levels between groups diminished considerably, but remained significant over the entire stabling period. The serum albumin level was low in the most seriously affected animals at the time of housing, but normal levels were restored within the first twelve weeks. In general, the number of parasite eggs in the faeces of the animals decreased, but there was considerable fluctuation. Apart from a single sampling date, no significant difference in egg per gram (EPG) could be demonstrated between the experimental groups during the stabling period.The calves were fed according to their age. The live weight differences between most and least affected groups diminished from 64 kg at the time of housing to 37 kg at the end of the stabling period. The reduction took place particularly during the first four weeks of housing.Considering both the grazing and stabling periods, it appeared that anthelmintic treatment twice during the period had no effect on the final live weight, whereas remeated treatments at three-week intervals resulted in an increase of 24 kg. Similarly, moving the animals to a clean pasture in mid-July resulted in an increase of 39 kg at the end of the stabling period when compared to calves which were not moved. Treatment of moved animals did not result in further body weight gain after seven months of housing.No significant correlation was found between parasite EPG of faeces and growth rate during the stabling period. However, a positive correlation was found between serum pepsinogen during the first eight weeks of housing and the weight gain over the entire stabling period. This was in contrast to the correlation experienced during the grazing period.     

Integrating local ecological knowledge,citizen science and long‐term historical data for endangered species conservation: Additional records of angel sharks (Chondrichthyes: Squatinidae) in the Mediterranean Sea

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Arsenic species: effects on and accumulation by tomato plants.

The uptake of arsenic (As) species by Lycopersicum esculentum, growing under soilless culture conditions, was studied. A 4 x 3 x 2 factorial experiment was conducted with four As species (arsenite, arsenate, methylarsonate, and dimethylarsinate), three As concentrations (1, 2, and 5 mg L(-)(1)) and two tomato cultivars (Marmande and Muchamiel). The phytoavailability and phytotoxicity were primarily determined by the As species. The concentrations of As in plant increased significantly with increasing As concentration in solution. Both MA and DMA showed a higher upward translocation than arsenite and arsenate, and treatments with MA and DMA clearly reduced plant growth and fruit yield. The As concentration in tomatoes treated with arsenite or arsenate were within the range considered normal in food crops; however, the As concentration in tomatoes treated with MA and DMA were close to or even above the maximum limit. When tomato plants are exposed to high concentrations of As in nutrient solutions, they may uptake As to concentrations unacceptable for human food.     

Death and Transfiguration of a Triple Junction in the South Atlantic

Three major lithospheric plates-Antarctic, South American, and African-meet in the South Atlantic near Bouvet Island where the Mid-Atlantic Ridge (MAR), the Southwest Indian Ridge (SWIR), and the American Antarctic Ridge converge toward a fast evolving triple junction. A major magmatic pulse has recently built a new, swollen segment of the SWIR (Spiess Ridge) that is propagating toward the MAR at a rate of 4 to 5 centimeters per year, disrupting a former ridge-ridge-ridge (RRR) triple junction. A new triple junction will be established about 70 kilometers to the north when the propagating SWIR/Spiess segment will impact with the MAR, probably within the next 1 million years. The American Antarctic Ridge will take advantage of the MAR/SWIR duel by capturing an approximately 70-kilometer stretch of MAR, whereas the Antarctic plate will increase its size.     

Wounds of the pastern and foot region managed with phalangeal casts: 50 cases in 49 horses (1995–2006)

Objective   Describe the use of a phalangeal cast as treatment for wounds in the pastern and foot region of horses. Secondly, to evaluate the healing and soundness of horses treated with phalangeal casts.
Design   Retrospective study of 49 horses.
Procedures   Medical records of 49 horses that were treated with a phalangeal cast for 50 cases of wounds in the pastern and foot region at equine referral hospitals from 1995 to 2006 were reviewed and follow-up information was obtained.
Results   Treatment consisted of wound debridement, lavage, wound closure (28 wounds), cast application and antibiotics (84%). At follow-up, the majority of horses were sound (42 of 47 wounds, 89.4%), three horses were still lame and one horse was euthanased because of persistent lameness. Three horses were lost to follow-up. There was no statistical difference between the outcomes of horses treated acutely (<24 h) or after a 24-h delay. Similarly, the involvement of synovial structures in the wound did not significantly influence outcome.
Conclusions   In this study, wounds involving the pastern and foot that were treated with a phalangeal cast carried a good prognosis for soundness (89.4%) and cosmetic healing (89.5%). The phalangeal casts were well-tolerated and effective.     

Treatment of anovulatory anoestrous postpartum dairy cows with a gonadotropin-releasing hormone (GnRH), prostaglandin F2𝛂, GnRH regimen or with progesterone and oestradiol benzoate

AIM: To compare 2 treatments for anovulatory anoestrus (AA) in postpartum dairy cows. The treatments were combinations of gonadotropin-releasing hormone (GnRH) and prostaglandin F_2𝛂 (PG) or progesterone (P4) and oestradiol benzoate (ODB).

METHODS: Forty AA cows from each of 5 herds were blocked by age (2 or >2 years old) and randomly assigned to 1 of 2 treatments. The first group (GPG) were treated with 250 𝛍g of a GnRH analogue, gonadorelin, followed 7 days later by 15 mg of the PG analogue, luprostiol. Two days later the cows were injected with 250 𝛍g of gonadorelin. Cows were artificially inseminated 16–24 h after the second GnRH injection. The second group (P4+ODB) were treated with an intravaginal P4 releasing device for 6 days, followed 24 h after device removal by injection of 1 mg of ODB. Cows were pregnancy tested 35–40 days after the initial insemination and twice again at 6–8 week intervals thereafter.

RESULTS: There was no significant difference between P4+ODB and GPG groups in the percentage of cows submitted for insemination in the first 7 days (94.0% vs 100% for P4+ODB vs GPG, respectively; p>0.3), in conception rate to first insemination within the first 7 days (43.6% vs 35.0% for P4+ODB vs GPG, respectively; p>0.2), in the percentage of cows conceiving in the first 28 days of the breeding period (68.0% vs 58.3%, P4+ODB vs GPG, respectively; p>0.1), or in median interval from the end of treatment to conception (20 vs 21days;p>0.1).

CONCLUSIONS: No differences in the reproductive performance of AA cows treated with either P4+ODB or GPG were detected. However, given the small number of animals enrolled, further data are required before the GPG protocol can be recommended for treatment of AA cows.