The lichens of the Scottish native pinewoods

During the last 30 years, 434 epiphytic lichen taxa have beenrecorded from the native pinewoods of Scotland. Of these lichens,about 219 have been recorded from the bark, lignum or stumpsof pine (Pinus sylvestris) itself. Eighteen species are, inthe British Isles, confined to these native pinewoods, whichare themselves confined to the Scottish Highlands. A resumeis presented of the habitats and niches available to lichensin the native pinewoods, using examples of the most characteristicspecies for each. The ‘pinewood habitat’ for epiphyticlichens is by no means restricted to pine, but also includesassociated trees, shrubs and subshrubs, especially birch, rowan,holly, aspen, juniper and heather. The strong east–westvariation in the composition of the lichen flora is outlined.By comparison of species lists from pinewood stands of knownancientness with those from mature plantations distant fromthe ‘core’ pinewoods, an additional c. 60 speciescan be considered as indicative of an ecological continuityof the pinewood habitat. From this pool of c. 77 species, aNative Pinewood Index of Ecological Continuity is presentedas a useful tool for biodiversity assessments of pinewoods.     

Diameter-Selective Raman Scattering from Vibrational Modes in Carbon Nanotubes

Single wall carbon nanotubes (SWNTs) that are found as close-packed arrays in crystalline ropes have been studied by using Raman scattering techniques with laser excitation wavelengths in the range from 514.5 to 1320 nanometers. Numerous Raman peaks were observed and identified with vibrational modes of armchair symmetry (n, n) SWNTs. The Raman spectra are in good agreement with lattice dynamics calculations based on C-C force constants used to fit the two-dimensional, experimental phonon dispersion of a single graphene sheet. Calculated intensities from a nonresonant, bond polarizability model optimized for sp2 carbon are also in qualitative agreement with the Raman data, although a resonant Raman scattering process is also taking place. This resonance results from the one-dimensional quantum confinement of the electrons in the nanotube.     

A laser ablation method for the synthesis of crystalline semiconductor nanowires

A method combining laser ablation cluster formation and vapor-liquid-solid (VLS) growth was developed for the synthesis of semiconductor nanowires. In this process, laser ablation was used to prepare nanometer-diameter catalyst clusters that define the size of wires produced by VLS growth. This approach was used to prepare bulk quantities of uniform single-crystal silicon and germanium nanowires with diameters of 6 to 20 and 3 to 9 nanometers, respectively, and lengths ranging from 1 to 30 micrometers. Studies carried out with different conditions and catalyst materials confirmed the central details of the growth mechanism and suggest that well-established phase diagrams can be used to predict rationally catalyst materials and growth conditions for the preparation of nanowires.     

Cumulus–Oocyte Communications in the Horse: Role of the Breeding Season and of the Maturation Medium

Horse is a seasonal breeder and information on oocyte quality outside the breeding season is very limited. Ovaries obtained at the slaughterhouse are a convenient but often limited source of oocytes in this species. As the low quantity of ovaries leads to an intensive use of all available material, it would be useful to know whether ovaries collected during the non‐breeding season are suitable for in vitro maturation (IVM). In an attempt to characterize the effect of season on oocyte quality, we investigated the permeability of the gap junctions (GJ) present between cumulus cells and oocytes because of their important role in oocyte growth and maturation. We also compared the effect of supplementing the maturation medium with bovine serum albumin (BSA) or oestrus mare serum (EMS). A total of 645 oocytes isolated from 158 and 154 ovaries collected during the breeding and the non‐breeding season, respectively, were used in this study. Oocytes were matured for 30 h in TCM 199 supplemented either with 10% EMS or with 4 mg/ml BSA. The presence of permeable GJs between cumulus cells and oocytes was investigated with the injection of a 3% solution of the fluorescent dye Lucifer yellow into the ooplasm. No differences in efficiency of oocyte retrieval or oocyte meiotic competence were detected between oocytes collected during the breeding and non‐breeding season. The vast majority (90%) of the oocytes collected during the breeding season had fully functional communications with their surrounding cumulus cells but such communications were completely interrupted in 55.3% of the oocytes collected during the non‐breeding season. During the non‐breeding season, the proportion of oocytes whose communications with cumulus cells were classified as closed or intermediate at the end of maturation was lower in the group matured with BSA than with EMS (71.4 vs 97.7, p < 0.05). The same trend, although not statistically significant, was observed during the breeding season also. The presence of BSA caused an incomplete cumulus expansion during both seasons. Our data indicate that oocytes collected during the non‐breeding season do not show any meiotic deficiency but lack active communication with the surrounding cumulus cells at the time of their isolation from the ovary. No data are available at present for determining the consequences on the developmental competence even if data from other species suggest that this is likely.     

Postovulatory Effect of Intravenous Administration of Lipopolysaccharide (E. coli,O55:B5) on the Contractile Activity of the Oviduct,Ova Transport,Binding of Accessory Spermatozoa to the Zona Pellucida and Embryo Development in Sows

The effect of lipopolysaccharide (LPS) (E. coli, O55:B5), administered 18 h after ovulation in the second oestrus after weaning, on the contractile activity of the oviduct, ova transport, sperm binding to zona pellucida (ZP) and embryo development, was studied in 14 Swedish crossbred (Landrace Yorkshire) multiparous sows. The endotoxin group (E‐group) sows were administered with 300 ng/kg of LPS while the control group (C‐group) sows were administered with 5 ml of saline i.v. via an indwelling jugular cannula. Immediately after evidence of standing oestrus, a Millar^® pressure transducer was placed intraluminally about 3 cm into the mid‐isthmus, via laparotomy. Pressure recordings of the oviduct were collected from all conscious sows until slaughter. After slaughter, the genital tract opposite to the side with the transducer was retrieved, and three equal isthmic segments and the first third of the uterine horn part adjacent to the utero‐tubal‐junction (UTJ) were flushed separately to recover the ova. The intervals (mean±SD) from ovulation to slaughter (OS) and insemination to ovulation (IO) were not different between the E‐group (44.5±5.7 h; 13.3±6.5 h) and the C‐group (42.7±5.9 h; 14.8±4.1 h), respectively. Ova recovery rate (RR) in the E‐group (80.2±22.9%) did not differ from that in the C‐group (85.2±4.5%). The frequency distribution of ova recovered in the different segments did not significantly (p>0.05) differ between the groups. The E‐group showed higher cleavage rate than controls. A higher proportion of spermatozoa bound to the ZP was also found in the E‐group compared with controls. The isthmic intraluminal pressure slightly increased (p=0.07) 18 h after ovulation and immediately following LPS in the E‐group, compared with the C‐group. The frequencies of phasic pressure fluctuations were significantly (p<0.05) lower at 30 and 38 h after ovulation in the E‐ than in the C‐group. It can be concluded from the present study that a single i.v. administration of LPS (300 ng/kg body weight) to sows, 18 h after ovulation might be associated with changes in isthmic pressure and the frequency of phasic pressure fluctuations, increased numbers of spermatozoa attached to the ZP and an enhanced embryo development but not with ova transport rates.     

Comparison of two injectable anesthetic regimes in feral cats at a large-volume spay clinic

Same‐day mass sterilization of feral cats requires rapid onset, short‐duration anesthesia. The purpose of this study was to compare our current anesthetic protocol, Telazol–ketamine–xylazine (TKX) with medetomidine–ketamine–buprenorphine (MKB). Feral female cats received either IM TKX (n = 68; 0.25 mL cat^?1; tiletamine 12.5 mg, zolazepam 12.5 mg, K 20 mg, and X 5 mg per 0.25 mL) or MKB (n = 17; M 40 µg kg^?1, K 15 mg kg^?1, and B 10 µg kg^?1). Intervals measured included time from injection to recumbency, time to surgery, duration of surgery, and time from reversal of anesthesia (TKX: yohimbine 0.50 mg cat^?1 IV; MKB: atipamezole 0.50 mg cat^?1 IM) to sternal recumbency. Following instrumentation (Vet/Ox 4403 and Vet/BP Plus 6500), physiological measurements were recorded at 5‐minute intervals, and included rectal temperature, heart rate (HR), respiratory rate (RR), SpO₂ (lingual or rectal probes), and indirect mean arterial blood pressure (MAP) (oscillometric method). Nonparametric means were compared using Mann–Whitney U‐tests. Parametric means were compared using a two‐factorial anova with Bonferroni's t‐tests. The alpha‐priori significance level was p < 0.05. Values were mean ± SD. Body weight (TKX: 2.9 ± 0.5 kg, MKB: 2.7 ± 0.7 kg), time to recumbency (TKX: 4 ± 1 minutes, MKB: 3 ± 1 minutes), time to surgery (TKX: 28 ± 7 minutes, MKB: 28 ± 5 minutes), and duration of surgery (TKX: 11 ± 7 minutes, MKB: 8 ± 5 minutes) did not differ between groups. In contrast, MKB cats required less time from reversal to sternal recumbency (TKX: 68 ± 41 minutes, MKB: 7 ± 2 minutes) and were recumbent for shorter duration (TKX: 114 ± 39 minutes, MKB: 53 ± 6 minutes). Temperature decreased during the study in both groups, but overall temperature was higher in MKB cats (38.0 ± 0.95 °C) than in TKX cats (37.5 ± 0.95 °C). RR, HR, and SpO₂ did not change during the study in either group. However, overall HR and RR were higher in TKX cats (RR: 18 ± 8 breaths minute^?1, HR: 153 ± 30 beats minute^?1) compared to MKB cats (RR: 15 ± 7 breaths minute^?1, HR: 128 ± 19 beats minute^?1). In contrast, overall SpO₂ was lower in the TKX group (90 ± 6%) compared to the MKB group (94 ± 4%). MAP was also lower in the TKX group (112 ± 29 mm Hg) compared to that in the MKB group (122 ± 20 mm Hg). However, MAP increased in the TKX group during surgery compared to pre‐surgical values, but did not change in the MKB group. The results of this study suggested that MKB might be more suitable as an anesthetic for the purpose of mass sterilization of feral female cats.     

Effects of buprenorphine,butorphanol or tramadol premedication on anaesthetic induction with alfaxalone in common marmosets (Callithrix jacchus)

Objective

To investigate the clinical and physiological effects of intravenous (IV) alfaxalone alone or in combination with buprenorphine, butorphanol or tramadol premedication in marmosets.

Disc extrusion in a Rottweiler dog with caudal cervical spondylomyelopathy after failure of intervertebral distraction/stabilisation

A Rottweiler dog was presented with an 8 week history of hindlimb ataxia. Neurological examination localised the lesion to the cervical spinal cord. Myelography demonstrated dynamic compressive lesions at C5-6 and C6-7 consistent with a diagnosis of caudal cervical spondylomyelopathy. Distraction/stabilisation of both discs was performed using interbody polymethyl methacrylate. Both implants subsequently failed leading to extrusion of the remaining dorsal annulus fibrosus of the C5-6 intervertebral disc and nonambulatory tetraparesis. A ventral slot combined with distraction/stabilisation using screws and polymethyl methacrylate was performed and resulted in nearly full neurological recovery.