Hookworm dermatitis due to Uncinaria stenocephala in a dog from Saskatchewan

Uncinaria stenocephala hookworm dermatitis (uncinariosis) was diagnosed on fecal examination and macerated skin biopsy in a 1.5-year-old greyhound dog from Saskatchewan. This is the first reported case in Canada. Treatment with moxidectin cleared gastrointestinal and dermal infections.     

Influence of nutrition and body condition on pituitary, ovarian, and thyroid function of nonlactating beef cows

Nonpregnant Hereford cows (n = 70) were used to determine the effect of nutrient intake and body condition on reproductive and thyroid function. Body condition scores (BCS; 1 = emaciated; 9 = obese) of cows averaged 5.0 +/- .2 on July 1, and cows were fed for 4 mo either to lose weight and BCS (thin; n = 22), to maintain weight and BCS (moderate; n = 24), or to gain weight and BCS (fat; n = 24). After November 1, cows received a complete ration to maintain weight and BCS. Cows were slaughtered in December (six thin, eight moderate, and eight fat cows) or the subsequent March (16 cows per group). Before slaughter, cows were given two injections of prostaglandin F2 alpha (PGF) 11 d apart. Six days after the second PGF injection, cows were simultaneously treated with 100 micrograms of gonadotropin releasing hormone (GnRH; i.m.) and 100 micrograms of thyrotropin releasing hormone (TRH; i.v.) and serum samples were obtained. The BCS of cows at slaughter (8 d after PGF) averaged 3.4, 5.3, and 7.1 (P less than .01) and carcass energy content averaged 243, 432, and 714 Mcal (P less than .01) for thin, moderate, and fat cows, respectively. Wet ovarian (P less than .001) and corpora lutea (P less than .01) weights were heavier for fat cows. Content of LH in the pituitary gland and concentrations of thyroxine (T4) in serum after GnRH/TRH were not influenced by nutrient intake or BCS. However, thin cows had greater concentrations (P less than .05) of LH in serum after GnRH/TRH than did moderate or fat cows. We conclude that nutrient intake and body energy reserves of beef cows influenced ovarian function and LH in serum after treatment with GnRH.     

The impact of harvester ants on decomposition, N mineralization, litter quality, and the availability of N to plants in the Mojave Desert

In arid areas of North America, nests of the seed-harvesting ant Pogonomyrmex rugosus tend to be elevated in mineral nitrogen and other soil nutrients relative to other microhabitats. We investigated the roles of decomposition, N mineralization, and plant nutrient uptake in maintaining high standing stocks of nutrients in P. rugosus ant nests. Decomposition rates of standard cellulose substrates placed on the surface of ant nests and other desert microhabitats suggest that conditions found in ant nests and bare areas are conducive to higher rates of decomposition than conditions under shrubs. In laboratory incubations of moist soil, net N mineralization rates were significantly higher in soil from ant nests than from bare areas and under two of three plant species. Net N mineralization rates measured in situ were much lower than those measured in laboratory incubations, but ant nest soil still exhibited higher rates at one of two sites. Litter collected from ant mounds, composed chiefly of seed chaff, was similar in N content to litter collected from underneath the dominant plant species, but had a significantly higher mean δ¹⁵N. Using this distinctive isotope signature as a tracer, we found no evidence that large perennial shrubs tap ant nests as a source of N. An invasive, annual grass species was significantly enriched in ¹⁵N, had higher leaf %N, and produced more seeds when growing on the mound than when growing several meters away; however P. rugosus nest surfaces are typically free of such annuals. We conclude that both high rates of nutrient cycling relative to other Mojave Desert microhabitats and low N utilization by the surrounding vegetation contribute to high standing stocks of mineral N in P. rugosus nests.     

Correction to: Restrictions on natural regeneration of storm‑felled spruce sites by silver birch (Betula pendula Roth) through limitations in fructification and seed dispersal

European Journal of Forest Research - The article “Restrictions on natural regeneration of storm-felled spruce sites by silver birch (Betula pendula Roth) through limitations in...     

Dynamic visualization of thrombopoiesis within bone marrow

Platelets are generated from megakaryocytes (MKs) in mammalian bone marrow (BM) by mechanisms that remain poorly understood. Here we describe the use of multiphoton intravital microscopy in intact BM to visualize platelet generation in mice. MKs were observed as sessile cells that extended dynamic proplatelet-like protrusions into microvessels. These intravascular extensions appeared to be sheared from their transendothelial stems by flowing blood, resulting in the appearance of proplatelets in peripheral blood. In vitro, proplatelet production from differentiating MKs was enhanced by fluid shear. These results confirm the concept of proplatelet formation in vivo and are consistent with the possibility that blood flow-induced hydrodynamic shear stress is a biophysical determinant of thrombopoiesis.     

Dynamics of Atmospheric Aerosol Number Size Distributions in the Eastern Mediterranean During the ��SUB-AERO�� Project

Measurements of number size distributions of submicron aerosols have been performed at the Eastern part of Mediterranean as part of an extensive measurement campaign to study photo-oxidants and aerosols (SUB-AERO Project). The measurements were made at the Finokalia station on the island of Crete (Greece) and onboard the research vessel ??Aegaeon??. Two campaigns were performed during July 2000 and January 2001 using two scanning mobility particle sizers. The particle distributions measured in the range between 7.8 < d _p < 327 nm during the summer measurements and between 7.5 < d _p < 316 nm during the winter measurements, where d _p is the mobility particle diameter. The concentration of ultrafine particles (7.5 < d _p < 30 nm) was higher during the winter period and varied mainly between 5 × 10¹ and 2 × 10³?cm^?3 with concentration peak values for this mode exceeding 1 × 10⁴?cm^?3. During the summer campaign, an average number concentration of 1 × 10²?cm^?3 at Finokalia and about 5 × 10¹?cm^?3 aboard the ??Aegaeon?? vessel was measured. An average concentration of 1 × 10³?cm^?3 was measured for the particles in the size range between 30 and 100 nm, whereas in the size range 100?C300 nm, the measured concentration ranged between 1 × 10² and 5 × 10³?cm^?3. Diurnal patterns in number concentrations were observed in connection with the transport of air masses and local sources. During the winter period, three nucleation events were observed in connection with the appearance of a particle mode at 20 nm.     

Congenital internal hydrocephalus in a quarter horse foal

Since the normal absorption of CSF occurs in the cerebral veins and venous sinuses, any obstruction to the normal flow and absorption of CSF will result in accumulation of CSF central to the site of obstruction. Such accumulation within the cranium is defined as hydrocephalus.A foal was presented with an enlarged and an abnormally-shaped skull, but with normal behavior. The filly's condition deteriorated. Radiographs showed a domeshaped cranial vault with compression of the frontal sinus region. Massive hydrocephalus with little normal cerebral tissue left was diagnosed with ultrasound.Surgery was attempted to relieve the pressure. Eventually the foal was euthanized. Post-mortem confirmed the radiographic and ultrasound diagnosis. Since there was a lack of demonstrable obstruction, the authors suspected the foal had suffered from the Arnold-Chiari syndrome.     

Uncertainty assessment of soya bean yield gaps using DSSAT‐CSM‐CROPGRO‐Soybean calibrated by cultivar maturity groups

Soya bean yield gap can be caused by different factors resulting in uncertainties when the objective is to use such information for farm decision‐making and reference yield determination. Thus, this study aimed to quantify the soya bean yield gap for four sites, located in Southern and Midwestern Brazil, as well as the uncertainties of that related to cultivars, sowing dates, soil types and reference yields. The crop simulation model DSSAT‐CSM‐CROPGRO‐Soybean was calibrated for cultivars with similar maturity groups, based on the data obtained from the best farmers at the county level. The yield gap by water deficit (YG_WD) was obtained through the difference between potential and attainable yields, and that one caused by sub‐optimum crop management (YG_CM) by subtracting actual yield of each county, obtained from official statistics between 1989/90 and 2014/15 growing seasons, from the estimated attainable yield. The yield was simulated using four sowing dates, three soil types and two soya bean maturity groups by county. The reference yield uncertainty was quantified using yield reference from crop model and regional winners of the soya bean yield context, conducted by CESB (Brazilian Soybean Strategic Committee), for the growing seasons from 2013/14 to 2015/16. The crop model showed a good agreement between measured and simulated crop development and growth using calibration by maturity group, with low root mean square error (347 kg/ha). Southern sites had a mean YG_WD of 1,047 kg/ha, while in the Midwest, it was lower than 100 kg/ha. The YG_CM was 1,067, 528, 984 and 848 kg/ha, respectively, for Castro, PR, Mamborê, PR, Montividiu, GO and Primavera do Leste, MT, representing the opportunity for yield gain when having the best farmers as reference. The maturity groups, sowing dates and soil types showed to be an important source of uncertainty for yield gap determination, being recommended to investigate the farms in detail for an appropriate quantification. The reference yield showed expressive uncertainties, with some farmers presenting conditions to increase their soya bean yields by more than 3,000 kg/ha, when considering as reference the yields obtained by the winners’ farmers. These results show that uncertainties must be reduced when assessing farm yield gaps, in order to ensure that expected rate of soya bean yield growth could be reached by adopting the same technologies from CESB winners and best farmers in the county as a reference.     

Transstadial and intrastadial experimental transmission of Ehrlichia canis by male Rhipicephalus sanguineus

The acquisition and transmission of rickettsial pathogens by different tick developmental stages has important epidemiological implications. The purpose of this study was to determine if male Rhipicephalus sanguineus can experimentally acquire and transmit Ehrlichia canis in the absence of female ticks. Two trials were performed where nymphal and male R. sanguineus were simultaneously acquisition fed on the same infected donor hosts, and transstadially or intrastadially exposed male ticks were fed on separate pathogen-free dogs as a test for transmission. A single-step p30-based PCR assay was used to test canine and tick hosts for E. canis infections before and after tick feeding. E. canis was detected after either intrastadial or transstadial passage in male ticks, the organism remained detectable in both tick groups after transmission feeding, and both tick groups transmitted the rickettsia to susceptible dogs. Infection of dogs via tick feeding resulted in milder clinical signs and lower antibody titers than intravenous inoculation of carrier blood, but further investigation is needed to understand the mechanisms responsible for this observation. These results demonstrate that male R. sanguineus can take multiple feedings, and that they can both acquire and transmit E. canis in the absence of female ticks. This tick development stage could be important in transmission of E. canis, and perhaps related pathogens, between vertebrate hosts under natural and experimental conditions.     

Cryopreservation of yellow-poplar and sweetgum embryogenic cultures

Cryopreservation has become anessential tool for operational application offorest tree embryogenic cultures, due to thelong evaluation periods needed for treesregenerated from these cultures. Fiveyellow-poplar (Liriodendron tulipifera)and seven sweetgum (Liquidambar spp.)embryogenic culture lines werestored in liquid nitrogen for 48 hours, afterwhich they were thawed and tested for regrowthand ability to produce somatic seedlings.Combinations of two sorbitol pretreatments andthree dimethylsulfoxide (DMSO) cryoprotectantlevels were evaluated for their impact onrecovery following cryogenic storage. The bestresults were obtained with 0.4 M sorbitol and5% DMSO, which provided 100% recovery.Somatic seedlings were regenerated from allculture lines and treatments, except for atransgenic sweetgum line.