Habitat characterization of Texas wild‐rice (Zizania texana Hitchcock), an endangered aquatic macrophyte from the San Marcos River,TX, USA

1. The habitat of Texas wild‐rice (Zizania texana Hitchcock), known only from the spring‐fed upper San Marcos River in Central Texas, was classified in terms of physical and chemical conditions, depth, current velocity, associated aquatic macrophytes, and substrate composition. 2. Randomly selected transects in sites with and without Texas wild‐rice were evaluated during May, August and January 1994–1995. Physical and chemical conditions (temperature, dissolved oxygen, specific conductance, pH) were found to be nearly constant and uniform both among transect types and sampling dates. Chemical analysis of the substrate likewise showed few differences among transect types. Turbidity was found to be significantly different among transect types on only one sampling date (Kα_0.05=0.60; p=0.009), but even non‐significant levels of turbidity may present biologically significant impacts to wild‐rice plants. 3. Differences in substrate particle size were highly significant (Kα_0.05=0.71; p=0.001) with Texas wild‐rice occupying sites having moderately coarse to coarse sandy soils (73%) compared with the moderately fine to fine clay soils found at non‐rice sites (82%). However, no significant differences were found in organic matter content among rice and non‐rice transects ( =2.09 and 2.56%, respectively). 4. Texas wild‐rice was found primarily in shallow areas of the river (<1 m) and at higher current velocities than those of non‐rice sites ( ≥0.46 m s⁻¹ and ≤0.22 m s⁻¹, respectively). 5. Texas wild‐rice appears to be more commonly associated with other native species rather than exotic species. Mean percentage composition of exotic macrophytes did not exceed 29% in areas where Texas wild‐rice grew, but they accounted for nearly 47% of the composition in areas where rice did not grow. 6. The results of this study will allow for reliable and accurate identification of the remaining suitable habitat of Texas wild‐rice in the San Marcos River for possible reintroduction and development of management plans. Copyright © 1999 John Wiley & Sons, Ltd.     

Effects of pre- and post-harvest anti-transpirant applications on vase life of leatherleaf fern

Post-harvest water use of leatherleaf fern (Rumohra adiantiformis [G. Forst] Ching) was not affected when Cloud Cover, Vapor Gard or Wilt Pruf¹ were applied 3–28 days prior to harvest. However, post-harvest anti-transpirant dips reduced water use during the first 24 h. The shortest vase life occurred in fronds dipped in water. The incidence of frond curl was not influenced by anti-transpirant applications.     

Experimental tuberculosis in red deer (Cervus elaphus)

This study was designed to investigate experimental Mycobacterium bovis infection of red deer (Cervus elaphus). Three intravenously inoculated deer (dose 10 microg-1000 microg) developed miliary tuberculosis of the lungs and all died within 28 days of being infected. No clinical illnesses were observed in four subcutaneously (dose 1 microg-1000 microg) and three intratracheally (dose 10 microg-100 microg) inoculated deer. At the conclusion of the experiment six weeks post inoculation, these seven animals reacted to 2 mg/ml of bovine purified protein derivative. The principal lesions in the intravenously inoculated deer were in the lungs which had multiple foci of necrosis containing very large numbers of acid fast bacilli. A gradation of changes was seen in the subcutaneously inoculated deer. The animal receiving the 1 microg dose only had lesions at the injection site and the draining prescapular lymph node. Deer receiving higher doses also had histopathological changes in the lungs and liver. Microscopic changes in the intratracheally infected animals were restricted to the thoracic cavity. The ability of the deer to controlled infection was related to the route of inoculation.     

Experimental Infection of Sheep and Goats with Caprine Arthritis-Encephalitis Virus

Sir, — The isolation of caprine arthritis-encephalitis virus (CAEV) from the carpal joint of a yearling goat with chronic interstitial pneumonia is reported in this issue of the Journal.⁽³⁾ We wish to report on the experimental infection of sheep and goats with this isolate of CAEV. Two 20-month-old Romney lambs (483, 485) and two 2-month-old feral goat kids (43, 45) were inoculated with CAEV suspension (10^4.0 median tissue culture infective doses [TCID₅₀ml]). Each animal was inoculated with 1.0 ml of virus suspension by each of the following routes: intravenous, intracerebral into the right cerebral hemisphere and intra-articularly into the right radio-carpal joint.⁽⁴⁾ An additional control lamb (490) and goat kid (44) were inoculated in identical fashion with cell culture fluid from uninfected goat synovial membrane cells.     

The potential of 44 native and non-native tree species for woodland creation on a range of contrasting sites in lowland Britain

A series of species trials were set up to investigate the establishmentand early growth (up to 14 years old) of 44 native and non-nativetree species on a variety of different site types in lowlandBritain. On good quality lowland afforestation sites, Platanusx hispanica (London plane) established and grew more successfullythan the native trees tested, and may be an example of a speciesthat could theoretically be established in anticipation of futureclimate change. Experiments on a variety of community woodlandsites indicated that a range of exotic species, such as X Cupressocyparisleylandii (Leyland cypress), may have the potential for establishinga woodland cover on poorly restored land where few other treeswould grow. However, on less challenging, better restored sites,a wide range of native species also grew successfully. Furtherlong-term and larger scale trials on a wider variety of sitesare required to confirm the potential of the species testedfor British conditions. The results from these experiments alsoshowed that relative growth rates of different species can varythrough time, highlighting the danger in making premature judgementsabout species suitability based solely on very early tree growth.     

Effects of supplemental dietary vitamin C on quality of semen from Nile tilapia (Oreochromis niloticus) breeders

The objective of this study was to evaluate the effects of vitamin C on growth and quality of semen from Oreochromis niloticus breeders. One hundred and sixty males were fed with different levels of vitamin C (0, 261, 599 and 942 mg/kg diet). The higher weight values were recorded for 599 (166 g) and 942 (175 g) mg of vitamin C/kg diet. Sperm motility, vigour and concentration were higher with 599 and 942 mg of vitamin C/kg diet. The semen volume, gonadosomatic index and plasma protein data from the last week showed a direct relationship with increasing levels of vitamin C. No changes were observed in the hepatosomatic index and blood glucose. The haematocrit and erythrocyte showed higher values estimated by equations derived at 850 and 638 mg vitamin C/kg diet, respectively. The leucocytes were inversely proportional to the increasing levels of vitamin C. After 100 days of feeding, animals fed the diet containing 942 mg vitamin C/kg diet had higher sperm motility, linearity, curvilinear velocity, straight line velocity and average path velocity (p < .05). Higher values of beat cross‐frequency were observed in broodfish fed diets containing 942 and 599 mg vitamin C/kg. The different vitamin C levels did not cause differences in straightness, lateral head displacement and sperm morphology. For Nile tilapia males on intensive rearing and handling conditions, vitamin C levels between 599 and 942 mg/kg may be used for a better performance and quality of semen.     

Status of Sensitivity of Northern German Botrytis Populations to the New Sdhi Fungicide Fluopyram Prior to its Release as a Commercial Fungicide

Journal of Plant Diseases and Protection - In a survey of Botrytis populations in Northern Germany in 2012-2014, an average of 67.7% and 73.8% of isolates from strawberry and raspberry fields...     

Induction of parturition in dairy cows with dexamethasone.

Sixty Holstein cows were paired by parity and sire, and one of each pair was allocated at random to treatment or control; 17 cows were injected with 7.5 mg/100 kg dexamethasone trioxa undecanoate 14 days before the predicted date of calving, 13 cows received the same dose five days before term and 30 cows were left untreated. The treatment significantly advanced parturition and 29 of the 30 induced cows calved within 72 hours of the injection. Induction at day 14 before term was safe for calf and dam, the calves were 3.2 kg lighter than control calves and there was a high incidence of retained placenta. Treatment for this condition resulted in increased veterinary costs of 14.50 pounds per cow exclusive of dexamethasone treatment. Treatment at this stage was also associated with low pregnancy rates in the next breeding season. Calves born after induction at five days before term were not significantly lighter than calves from control cows, the problem of retained placenta was less marked and there were no subsequent effects on fertility. There were no significant effects of induction on milk yield or milk quality up to 200 days of lactation.     

Inclined running increases pulmonary haemorrhage in the Thoroughbred horse

REASONS FOR PERFORMING STUDY: Capillary stress failure-induced (exercise-induced) pulmonary haemorrhage (EIPH) during intense running in horses is thought to involve both intravascular (i.e. mean pulmonary arterial pressure [Ppa] > 100 mmHg) and extravascular (e.g. negative inspiratory pressure swings) mechanisms. HYPOTHESIS: That inclined running would reduce breathing frequency (coupled to stride frequency) and increase tidal volume thus increasing lung volume changes and intrapleural pressure swings resulting in more pronounced EIPH. METHODS: Six Thoroughbred horses were run to volitional fatigue (incremental step test) on a level (L) and inclined (I; 10%) treadmill in random order. Pulmonary minute ventilation, arterial blood gases and mean Ppa were obtained during each run while EIPH severity was quantified via bronchoalveolar lavage (BAL) 30 mins post run. RESULTS: Time to fatigue did not differ between trials (P > 0.05). At end-exercise, breathing frequency was reduced (L, 127.8 +/- 3.0; I, 122.6 +/- 2.1 breaths/min; P < 0.05) and tidal volume increased (L, 11.5 +/- 0.6; I, 13.1 +/- 0.5 L; P < 0.05) during inclined running. No differences existed in end-exercise plasma [lactate] between trials (L, 24.5 +/- 2.9; I, 26.2 +/- 3.4 mmol/l, P > 0.05); however, the mean peak Ppa was reduced during the inclined run (L, 105+5; I, 96 +/- 4 mmHg, P < 0.05). In the face of reduced Ppa, EIPH severity was increased significantly (P < 0.05) during the inclined vs. level run (L, 37.0 +/- 11.7; I, 49.6 +/- 17.0 x 10(6) red blood cells/ml BAL fluid). CONCLUSIONS: Although inclined running lowered peak Ppa, EIPH severity was increased. It is likely that this effect resulted, in part, from an altered ventilatory pattern (i.e. increased tidal volumes and associated intrapleural pressure changes). POTENTIAL RELEVANCE: This conclusion supports an important role for extravascular factors in the aetiology of EIPH.