Regional Patterns of Streamwater Acidity and Catchment Afforestation in Galloway,SW Scotland

This paper investigates the regional relationships between highflow water chemistry and conifer forest cover in 95 streamsspread over an area of approximately 2000 km² in Galloway,south-west Scotland, paying particular attention to the use ofdetailed catchment area data. Catchment forest data areextracted from a 30 m resolution tree height map derived fromsatellite imagery; geology data from a digital geology map; andaltitude and slope data from a 50 m resolution Digital TerrainModel (DTM). The results show that over the entire region pHlevels are lower with increasing catchment afforestation whilstaluminium concentrations are higher. Concentrations of sulphate arealso higher with increasing afforestation, which suggests thatconifers play a primary role in increasing the acidity levels ofstreams by exacerbating aerial acid deposition in the entireregion.     

A quantitative summary of nutrition support services in a veterinary teaching hospital

A full-time nutrition support service provided 1,133 consultations in a small animal teaching hospital from July 1986 to June 1988, consisting of 840 dogs, 260 cats, 23 exotic species, and 10 consultations with incomplete information. The dog and cat consultations represented 2.1 and 3.7% of canine and feline admissions, respectively. Consultations involved the determination of nutritional goals which led to recommendations of specific dietary regimens. Most frequent requests were for diet evaluation and diet formulation to meet estimated calorie and protein needs during illness and stress (23%), for specific calorie or nutrient modification given a working diagnosis (23%), and for avoidance of tissue utilization or weight loss (23%). Frequently involved single organ systems were gastrointestinal (16%), liver (12%), kidney (9%), and pancreas (4%), but multiple system involvement was more common (19%). Most frequent diagnostic categories were metabolic disorders (17%), chronic organ failure (17%), and neoplasia (12%). Enteral nutrition was preferred for 98% of consultations. Voluntary consumption was deemed adequate in 81% of consultations, and highly palatable balanced homemade diets and specialty products were recommended in 74% of these. Human hospital liquid enteral products were used in 95% of consultations recommending involuntary feeding, either fed alone, blended with petfoods, or supplemented with modules of protein or fat. The service demonstrated that full-time nutrition support can be utilized effectively in a small animal teaching hospital. Further development of such services will depend on research focused especially on determination of case-specific nutritional goals, patient responses, and cost effectiveness.     

Clinical nutrition of sheep and goats

Management systems and client goals are integral components of clinical nutrition and vary among and within sheep and goat producers. Evaluation includes client interview and history taking, record examination, forage analyses, animal examination, and occasionally blood or tissue assays. The types of nutritional disorders that are likely to be observed in sheep and goats vary according to the type of management and can be grouped according to feedlot, intensive production, farm flocks, dairy, and browse systems. Examples described include nutritional problems that may be overlooked (water deprivation), widespread (energy imbalance), currently difficult to prevent and treat (selenium deficiency), and reflective of soil-plant-animal complexities (copper-molybdenum balance).     

Imaging residue transfer into egg yolks

Prediction models for residue transfer into eggs are being developed. Recent results indicate that the developing egg yolk serves as an important storage depot for chemical residues. The current study was conducted to visualize incorporation and potential compartmentalization of drug residues in developing egg yolks. To this end, the drug magnevist was injected into hens to evaluate drug transfer into either early- or late-developing yolks. High-resolution magnetic resonance images (MRI) of drug residues in eggs were acquired using a 1.5 T Siemens Magnetom clinical scanner. A 10-cm circular surface coil was used for receiving the magnetic resonance signal. The eggs were positioned inside the coil cavity for an improved signal to noise ratio (SNR). Gradient-echo images were used to locate the centers of the eggs and to prescribe the position of the high-resolution image slab. The images were recorded using an inversion time (T1) weighted magnetization-prepared, rapid acquisition, gradient-recalled-echo (MPRAGE) pulse sequence. The sequence parameters used were as follows: repetition time (TR) equals 12 ms, echo time (TE) equals 5 ms, field of view (FOV) equals 200, TI = 10 ms, 1.25-mm slice thickness, and a matrix of 200 x 256. Following dosing, images of drug residues in eggs indicate that drugs can be incorporated and compartmentalized into ring structures within individual developing egg yolks. These results have significant human food safety implications because even after only a single dose, sequestered drug residues may be stored and later released to contaminate eggs for days to weeks after dosing.     

Learning-induced LTP in neocortex

The hypothesis that learning occurs through long-term potentiation (LTP)- and long-term depression (LTD)-like mechanisms is widely held but unproven. This hypothesis makes three assumptions: Synapses are modifiable, they modify with learning, and they strengthen through an LTP-like mechanism. We previously established the ability for synaptic modification and a synaptic strengthening with motor skill learning in horizontal connections of the rat motor cortex (MI). Here we investigated whether learning strengthened these connections through LTP. We demonstrated that synapses in the trained MI were near the ceiling of their modification range, compared with the untrained MI, but the range of synaptic modification was not affected by learning. In the trained MI, LTP was markedly reduced and LTD was enhanced. These results are consistent with the use of LTP to strengthen synapses during learning.     

Prognostic Value of Various Spermatological Attributes as Predictors of Zona Binding and Zona Penetration of Buffalo (Bubalus bubalis) Semen

Twenty‐four ejaculates from six (four ejaculates each) Surti buffalo bulls aged 4–8 years were used to assess various attributes of spermatozoa influencing the zona‐binding and zona‐penetration tests. Ejaculates from each bulls were subjected to in vitro sperm‐‐zona binding and sperm‐‐zona penetration tests (four replicates per bull) using immature buffalo oocytes. The average number of spermatozoa bound per oocyte was 27.79 ± 5.90. The average number of spermatozoa penetrated per oocyte was 3.35 ± 0.64. The average number of zona‐bound and ‐penetrated spermatozoa differed significantly between animals. Significant difference (p < 0.05) was observed between the plasmalemma integrity as assessed by eosin‐‐nigrosin stain and hypo‐osmotic swelling (HOS) test. Furthermore, the percentage of cells positive for the HOS test, i.e. functional membrane integrity (51.25 ± 2.32) was significantly (p < 0.05) higher than hypo‐osmotic swelling‐Giemsa (HOS‐G) test, i.e. the subpopulation of spermatozoa positive for functional membrane and acrosomal integrities (42.87 ± 4.56). The HOS test had significant correlations with plasmalemma integrity as measured by the vital stain, eosin‐‐nigrosin (r = 0.85, p < 0.05). The HOS‐G test also had significant correlation with plasmalemma integrity measured by vital stains such as eosin‐‐nigrosin (r = 0.90, p < 0.05) and fluorogenic stains [carboxyfluorescein diacetate (CFDA) and propidium iodide (PI); r = 0.92, p < 0.01] and HOS test (r = 0.93), acrosomal integrity (r = 0.86, p < 0.05) and mitochondrial membrane potential (r = 0.99, p < 0.01). The plasmalemma integrity (fluorogenic stain), functional membrane integrity (HOS test), subpopulation of spermatozoa positive for functional membrane and acrosomal integrities (HOS‐G test) and mitochondrial membrane potential had significant (p < 0.05) correlation with sperm zona binding and penetration. The present study indicates that these parameters could represent important determinants of sperm quality influencing zona binding and penetration.