Learning Neuroscience with Technology: A Scaffolded, Active Learning Approach.

Mobile applications (apps) for learning technical scientific content are becoming increasingly popular in educational settings. Neuroscience is often considered complex and challenging for most students to understand conceptually. iNeuron is a recently developed iOS app that teaches basic neuroscience in the context of a series of scaffolded challenges to create neural circuits and increase understanding of nervous system structure and function. In this study, four different ways to implement the app within a classroom setting were explored. The goal of the study was to determine the app's effectiveness under conditions closely approximating real-world use, and to evaluate whether collaborative play and student-driven navigational features contributed to its effectiveness. Students used the app either individually or in small groups, and used a version with either a fixed or variable learning sequence. Student performance on a pre- and post- neuroscience content assessment was analyzed and compared between students who used the app and a control group receiving standard instruction, and logged app data were analyzed. Significantly greater learning gains were found for all students who used the app compared to control. All four implementation modes were effective in producing student learning gains relative to controls, but did not differ in their effectiveness to one another. In addition, students demonstrated transfer of information learned in one context to another within the app. These results suggest that teacher-led neuroscience instruction can be effectively supported by a scaffolded, technology-based curriculum which can be implemented in multiple ways to enhance student learning.

Risk factors associated with veterinary attrition from clinical practice: a descriptive study.

A sustainable workforce is important for the veterinary profession to meet the demands of society. To maintain a sustainable workforce, it has been recommended to retain veterinary clinicians. However, there seems to be an increasing issue with retention of veterinarians in clinical practice. In the following study, the researchers sought to understand the associations between demographic and work-related factors and attrition of veterinarians from clinical practice. Responses to an online cross-sectional survey of 881 current and former Australian veterinary clinicians were analysed. A logistic regression model was used to identify and describe associations between attrition from veterinary clinical practice and salary, working hours, role in practice, years of experience, field of work, interaction with regulatory authorities, region of work and on-call duties. Lower salary, longer working hours, having on-call duties and having worked in both rural and metropolitan regions were found to significantly (P < 0.05) increase the likelihood of leaving clinical practice. The results may inform intervention strategies to assist the industry to retain veterinarians in clinical practice.

Animal Welfare Worldwide, the Opinion of Practicing Veterinarians.

The objective of this study was to investigate the animal welfare issues considered the most important by companion animal veterinarians worldwide. For this purpose, a global survey of several potential animal welfare issues was distributed via SurveyMonkey® in multiple languages. The distribution of survey responses differed by region. The main animal welfare concern reported worldwide was obesity, although there were differences across regions, possibly due to cultural and socioeconomic factors. Anthropomorphism (attributing human qualities or characteristics to an animal) was an issue in western countries but less so in Asia, Africa, and Oceania. There were significant differences between Asia and Europe, Africa, and Oceania in the importance and prevalence of convenience euthanasia. There were also age and sex differences in participant responses, with older veterinarians reporting fewer welfare problems than younger veterinarians, and female veterinarians reporting more welfare issues than their male counterparts.

How decision-making about euthanasia for animals is taught to Australasian veterinary students.

This study set out to explore how euthanasia decision-making for animals was taught to students in eight Australasian veterinary schools. A questionnaire-style interview guide was used by a representative at each university to interview educators. Educators were interviewed about their teaching of euthanasia decision-making for four categories of animals: livestock, equine, companion and avian/wildlife. Using thematic analysis, the terms provided by participants to describe how (mode of teaching) and what (specific content) they taught to students were categorised. Information about content was categorised into human-centred factors that influence decision-making, and animal-based indicators used to directly inform decision-making. All eight representatives reported some teaching relevant to euthanasia decision-making at their university for livestock, companion animal and avian/wildlife. One representative reported no such teaching for equid animals at their university. Observation of a euthanasia case was rarely reported as a teaching method. Five universities reported multiple modes of teaching relevant information, while two universities made use of modalities that could be described as opportunistic teaching (e.g., 'Discussion of clinical cases'). Factors taught at most universities included financial considerations, and that it is the owner's decision to make, while animal-based indicators taught included QoL/animal welfare, prognosis and behaviour change. Overall, most universities used a variety of methods to cover relevant material, usually including lectures and several other approaches for all animal types. However, because two universities relied on presentation of clinical cases, not all students at these veterinary schools will be exposed to make, or assist in making, euthanasia decisions.

How management of grief associated with ending the life of an animal is taught to Australasian veterinary students.

OBJECTIVE: Veterinarians have an important role in supporting and understanding their clients' grief. Veterinary schools have a duty to teach students how best to manage grief - both that of the students/future veterinarians and the clients. This study explores how grief management, associated with ending the life of an animal, was taught to students in eight Australasian veterinary schools. METHODS: A questionnaire-style interview guide was used by a representative at each university to conduct structured interviews with educators in a snowball sampling approach. Educators were interviewed about the teaching of grief management for four categories of animals: livestock, equine, companion and avian/wildlife. The terms used by participants to describe what they taught were grouped into common themes. Teaching was defined by individual participants and included structured and unstructured approaches. The stage in the degree (preclinical or clinical years) that grief management was taught in the veterinary curriculum and by whom (e.g. clinicians or psychologists) is also described. RESULTS: Grief management was taught more in preclinical than clinical years. However, due to how grief was characterised, much of this teaching was general 'nonspecific' teaching that included all categories of animals. Client grief was taught more generically, whereas, grief of veterinarians was taught using specific examples given by clinicians. CONCLUSION: A more robust end-of-life (EoL) management curriculum that includes all aspects of grief management is likely to increase job satisfaction, client happiness and professional satisfaction.

A pilot study of Australian pet owners who engage in social media and their use, experience and views of online pet health information.

OBJECTIVE: The aim of this study was to gain a better understanding of Australian pet owners' use of the internet for pet health; how trustworthy they rate various pet health information sources and the use of online information in subsequent veterinary consultations. METHOD: An anonymous questionnaire was developed, consisting of 30 questions, and distributed between March 2018 and May 2018 using convenience sampling through social media venues including Facebook and Twitter. All respondents were over the age of 18, lived in Australia and owned a pet animal. RESULTS: A total of 228 responses were received. The most common sources of pet health information were veterinarians (88.2%) and internet websites (81.1%). Most respondents reported using the internet 'many times per day' at either home or work. The majority of respondents used the internet to seek pet health information either 'not weekly but at least once a month' or 'less than once a month'. Nearly half of the respondents stated that they only 'sometimes' discuss their online findings with their veterinarian. Approximately one half of respondents agreed with the statement that online pet health information had affected their decision about whether to take their pet to the veterinarian. CONCLUSION: This study assesses how pet owners use the internet for pet health information and the role veterinarians can play in helping to facilitate these searches with tools such as information prescriptions. Further large-scale research is needed to help further understand this increasingly important aspect of pet health.

Pilot study of Australian veterinarians and their perceptions and experiences related to online pet health information.

OBJECTIVE: Investigate Australian veterinarians' perceptions of clients' use of the internet to find pet health information. METHODS: An anonymous online survey was distributed using social media, e-newsletters and veterinary magazines. RESULTS: A total of 85 complete responses were obtained from Australian veterinarians. Most (80%) reported believing that > 80% of their clients have access to the internet at home or work, but 68% thought that the majority of their clients do not understand what they read online. Attitudes regarding the impact of online pet health information on the veterinarian-client relationship were mixed (56% reported negative impact and 33% a positive impact), as well as for clients' use of the internet for information on companion animal health (47% reported negative impact and 38% a positive impact). When asked how often they suggest specific websites to their clients ('information prescriptions'), the majority of veterinarians reported that this is done infrequently. CONCLUSION: This pilot study highlighted the perception of Australian veterinarians of their clients' use of the internet to find pet health information. It also highlighted the need for a large-scale, detailed survey of Australian veterinarians and their views in relation to pet owners and their use of online information. This should include evaluation of information prescriptions and their potential benefits for clients and patients.

The emergence of a new strain of porcine circovirus-2 in Ontario and Quebec swine and its association with severe porcine circovirus associated disease--2004-2006.

In the late fall of 2004 more severe lesions of porcine circovirus-2 associated disease (PCVAD) than usual occurred during an outbreak of porcine circovirus-2 (PCV-2) infection in Ontario nursery and grower/finisher pigs. The lesions were of unprecedented severity and included diffuse bronchointerstitial pneumonia, granulomatous enteritis, vasculitis, interstitial nephritis, and new lesions of splenic infarction. Some affected herds had up to 50% mortality. The outbreak correlated with the sudden emergence of a variant PCV-2, with PCR restriction fragment length polymorphism (RFLP) type 321. Phylogenetic comparison of ORF2 sequences and full genome sequences showed the new variant to be different from the previously dominant RFLP type 422 viruses, and similar to viruses that had occurred in France and other European and Asian countries. A subsequent retrospective study showed a statistically significant increase in the frequency of histological lesions in lymph node, spleen, lung, small intestine, colon and kidney, for pigs spontaneously infected with RFLP type 321, compared with the older RFLP type 422 strain. Viral burden, based on IHC staining in lymph node, also showed a statistically significant increase in pigs infected with the newer variant RFLP type 321, compared with the older RFLP type 422 strain. This enhanced virulence in pigs infected with PCV-2 RFLP type 321 strain may be related to the genetic differences in this new strain of PCV-2. This virus is now the dominant strain of PCV-2 virus found in Ontario and Quebec swine.

Mitoprotective therapy preserves chondrocyte viability and prevents cartilage degeneration in an ex vivo model of posttraumatic osteoarthritis.

No disease-modifying osteoarthritis (OA) drugs are available to prevent posttraumatic osteoarthritis (PTOA). Mitochondria (MT) mediate the pathogenesis of many degenerative diseases, and recent evidence indicates that MT dysfunction is a peracute (within minutes to hours) response of cartilage to mechanical injury. The goal of this study was to investigate cardiolipin-targeted mitoprotection as a new strategy to prevent chondrocyte death and cartilage degeneration after injury. Cartilage was harvested from bovine knee joints and subjected to a single, rapid impact injury (24.0 ±1.4 MPa, 53.8 ± 5.3 GPa/s). Explants were then treated with a mitoprotective peptide, SS-31 (1µM), immediately post-impact, or at 1, 6, or 12 h after injury, and then cultured for up to 7 days. Chondrocyte viability and apoptosis were quantified in situ using confocal microscopy. Cell membrane damage (lactate dehydrogenase activity) and cartilage matrix degradation (glycosaminoglycan loss) were quantified in cartilage-conditioned media. SS-31 treatment at all time points after impact resulted in chondrocyte viability similar to that of un-injured controls. This effect was sustained for up to a week in culture. Further, SS-31 prevented impact-induced chondrocyte apoptosis, cell membrane damage, and cartilage matrix degeneration. CLINICAL SIGNIFICANCE: This study is the first investigation of cardiolipin-targeted mitoprotective therapy in cartilage. These results suggest that even when treatment is delayed by up to 12 h after injury, mitoprotection may be a useful strategy in the prevention of PTOA. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 9999:1-10, 2018.

LRH-1 mitigates intestinal inflammatory disease by maintaining epithelial homeostasis and cell survival.

Epithelial dysfunction and crypt destruction are defining features of inflammatory bowel disease (IBD). However, current IBD therapies targeting epithelial dysfunction are lacking. The nuclear receptor LRH-1 (NR5A2) is expressed in intestinal epithelium and thought to contribute to epithelial renewal. Here we show that LRH-1 maintains intestinal epithelial health and protects against inflammatory damage. Knocking out LRH-1 in murine intestinal organoids reduces Notch signaling, increases crypt cell death, distorts the cellular composition of the epithelium, and weakens the epithelial barrier. Human LRH-1 (hLRH-1) rescues epithelial integrity and when overexpressed, mitigates inflammatory damage in murine and human intestinal organoids, including those derived from IBD patients. Finally, hLRH-1 greatly reduces disease severity in T-cell-mediated murine colitis. Together with the failure of a ligand-incompetent hLRH-1 mutant to protect against TNFα-damage, these findings provide compelling evidence that hLRH-1 mediates epithelial homeostasis and is an attractive target for intestinal disease.

Students' opinions on welfare and ethics issues for companion animals in Australian and New Zealand veterinary schools.

OBJECTIVE: To determine what veterinary students in Australia and New Zealand consider important competences in companion animal welfare and ethics (AWE) required on their first day of practice, and to explore how their priorities relate to gender and stage of study. METHODS: Undergraduate students at all veterinary schools in Australia and New Zealand were sent an online survey. A subset of questions required participants to rank the importance of preselected AWE topics pertaining to companion animals. Data were analysed to determine differences in the way students of different gender or academic stage prioritised each of these AWE topics. RESULTS: Of 3220 currently enrolled students, 851 participated in the survey: 79% were female, 17% male, 4% unspecified. Ranking of the AWE topics, from highest to lowest importance, was: neutering, companion animal husbandry, euthanasia, behaviour and training, animal breeding, over-servicing in relation to animal needs and cosmetic surgery. Female students consistently ranked competency in AWE issues surrounding neutering more highly than male students (P = 0.006). Students in senior years of study ranked the importance of competency in animal abuse/hoarding (P = 0.048), shelter medicine (P = 0.012) and animal breeding (P = 0.002) less highly than those in junior years. CONCLUSIONS: Australasian veterinary students placed more importance on competency in AWE issues associated with clinical practice (such as neutering and euthanasia) than on professional behaviours (such as over-servicing and animal breeding). However, we consider that emphasis should still be placed on developing graduate competency in the latter categories to reflect growing societal concerns about companion animal over-supply and inappropriate professional conduct.

Dyspepsia in the community is linked to smoking and aspirin use but not to Helicobacter pylori infection.

BACKGROUND: The relationship between Helicobacter pylori infection and symptoms remains controversial. We aimed to determine if an association exists between unexplained dyspepsia (pain or discomfort centered in the upper part of the abdomen) and H pylori. METHODS: A validated questionnaire was completed by 592 healthy blood donors. Helicobacter pylori serologic values (via enzyme-linked immunosorbent assay), blood group status, and Rh status were measured; 4.9% of subjects who had a history of peptic ulcer disease were excluded from the analyses. RESULTS: The prevalence of dyspepsia and no ulcer history was 11% (95% confidence interval [CI], 8.6%-13.8%); 15.4% of subjects with dyspepsia had H pylori while 14.6% of subjects without dyspepsia were infected (P=.90). The mean dyspepsia impact scores (combining frequency and severity) in those with and without H pylori were 4.7 and 5.4, respectively (P=.20). The median H pylori optical density values in dyspepsia vs no dyspepsia were not significantly different (P=.30). Independent risk factors for dyspepsia were the use of aspirin (odds ratio [OR], 2.2; 95% CI, 1.3-3.7) and smoking (OR, 2.1; 95% CI, 1.3-3.6) but not age, sex, marital status, educational level, income, or the use of alcohol, coffee, or nonsteroidal anti-inflammatory drugs. Independent risk factors for H pylori were increasing age (OR, 1.8 per decade; 95% CI, 1.5-2.3), male sex (OR, 2.1; 95% CI, 1.3-3.4), and net family income (OR, 1.8; 95% CI, 1.2-3.3). CONCLUSION: Dyspepsia in the community is linked to smoking and aspirin use, but not to H pylori infection.

Facilities, breed and experience affect ease of sheep handling: the livestock transporter's perspective.

An understanding of the perceived importance of a variety of factors affecting the ease of handling of sheep and the interactions between these factors is valuable in improving profitability and welfare of the livestock. Many factors may contribute to animal behaviour during handling, and traditionally these factors have been assessed in isolation under experimental conditions. A human social component to this phenomenon also exists. The aim of this study was to gain a deeper understanding of the importance of a variety of factors affecting ease of handling, and the interactions between these from the perspective of the livestock transporter. Qualitative interviews were used to investigate the factors affecting sheep behaviour during handling. Interview transcripts underwent thematic analysis. Livestock transporters discussed the effects of attitudes and behaviours towards sheep, helpers, facilities, distractions, environment, dogs and a variety of sheep factors including breed, preparation, experience and sex on sheep behaviour during handling. Transporters demonstrated care and empathy and stated that patience and experience were key factors determining how a person might deal with difficult sheep. Livestock transporters strongly believed facilities (ramps and yards) had the greatest impact, followed by sheep experience (naivety of the sheep to handling and transport) and breed. Transporters also discussed the effects of distractions, time of day, weather, dogs, other people, sheep preparation, body condition and sheep sex on ease of handling. The concept of individual sheep temperament was indirectly expressed.

Transmission dynamics of a zoonotic pathogen within and between wildlife host species.

The transmission dynamics of the cowpox virus infection have been quantified in two mixed populations of bank voles (Clethrionomys glareolus) and wood mice (Apodemus sylvaticus), through analyses of detailed time-series of the numbers of susceptible, infectious and newly infected individuals. The cowpox virus is a zoonosis which circulates in these rodent hosts and has been shown to have an adverse effect on reproductive output. The transmission dynamics within species is best described as frequency dependent rather than density dependent, contrary to the 'mass action' assumption of most previous studies, both theoretical and empirical. Estimation of a transmission coefficient for each species in each population also allows annual and seasonal variations in transmission dynamics to be investigated through an analysis of regression residuals. Transmission between host species is found to be negligible despite their close cohabitation. The consequences of this for the combining ability of hosts as zoonotic reservoirs, and for apparent competition between hosts, are discussed.

Differential expression of IGF-I and IGF-binding protein-1 and -2 in periportal and perivenous zones of rat liver.

IGF-I has important roles in regulating growth and metabolism. Circulating IGF-I is bound to specific binding proteins (IGFBP-1 to -6), with hepatocytes containing IGF-I, IGFBP-1 and -2 mRNA. Although many hepatic proteins are regionally expressed in the liver acinus, no studies have reported zonation of IGF protein expression. In this study we investigated the pattern of hepatic mRNA for the IGF proteins, vs the previously reported pepriportal gradient of phosphoenolpyruvate carboxykinase (PEPCK) expression. In situ hybridisation was used to analyse IGF-I, IGFBP-1, -2 and PEPCK mRNA in female Sprague-Dawley rats fed diets containing low (6%), normal (21%) or high (35%) protein. We report for the first time that IGFBP-1 and -2 and IGF-I are differentially expressed in the liver acinus. In the normal- and high-protein groups, levels of IGFBP-1 mRNA were higher in the perivenous region, i.e. the opposite gradient to PEPCK, with a higher gradient of IGFBP-1 expression in the high-protein group. In contrast, IGFBP-2 had a similar pattern to PEPCK, and a periportal gradient of IGF-I mRNA was also seen in the low-protein group. Using computerised image analysis, levels of IGFBP-1 and -2 mRNA were elevated 2- and 10-fold respectively, in the low- vs normal-protein groups. The level of IGF-I mRNA was reduced to 65% of normal, with circulating IGF-I levels at 30% and insulin levels 39% of normal. These results demonstrate that hepatocytes are a heterogeneous population with respect to regulation of IGF proteins, having specific expression patterns dependent on the position of the hepatocyte within the liver acinus.

Glutamate concentration in plasma, erythrocyte and muscle in relation to plasma levels of insulin-like growth factor (IGF)-I, IGF binding protein-1 and insulin in patients on haemodialysis.

Elevated insulin-like growth factor binding protein (IGFBP) levels, including IGFBP-1, occur in renal failure, and may contribute towards reduced IGF bioactivity in uraemia. The reduced IGF bioactivity may, in turn, contribute towards the disturbances in protein metabolism present in renal failure. In this study, the relationships between intra- and extracellular amino acid (AA) levels and IGF-I and/or IGFBP-1 levels were studied in 30 adult patients (aged 24-70 years) on haemodialysis who had no clinical signs of malnutrition. Blood samples (n = 30) and muscle biopsies (n = 13) were collected for determination of free AA in erythrocytes (RBC), plasma and muscle by reverse-phase HPLC while IGFBP-1, IGF-I and insulin plasma levels were determined by radioimmunoassay The patients on haemodialysis had elevated glutamate concentrations in RBC and plasma compared with healthy controls (524 +/- 26 vs 448 +/- 17 mumol/l, P < 0.05 and 45 +/- 4 vs 32 +/- 4 mumol/l, P < 0.01 respectively), although glutamate levels in muscle were within the normal range. The mean IGF-I level was slightly increased (s.d. score +0.74 +/- 0.30) but insulin levels were within the normal range. IGFBP-1 levels, which were inversely correlated to insulin (r = -0.40, P < 0.02), were elevated threefold compared with controls. No plasma AA level displayed a significant correlation with IGF-I, IGFBP-1 or insulin levels. However, glutamate concentrations in RBC were positively correlated to IGFBP-1 (r = 0.51, P < 0.01) and inversely correlated to IGF-I (r = -0.46. P < 0.01), although unrelated to insulin. Muscle glutamate, which was inversely related to RBC glutamate, displayed an opposite pattern with an inverse relation to IGFBP-1 levels (r = - 0.73, P < 0.01) and a positive correlation to IGF-I levels (r = 0.64, P < 0.02). Glutamate was the only AA to display an inverse correlation between RBC and muscle (r = -0.65, P < 0.02, n = 12). These findings lead us to propose that, in uraemia, the elevated IGFBP-I levels, which reduce the bioavailability of IGFs, are linked to glutamate uptake in muscle, resulting in accumulation of RBC glutamate. Whether there is a causal relationship or the correlation is due to some common regulator is not clarified in the present study.

Regulation of insulin-like growth factor-binding protein-3 ternary complex in feline diabetes mellitus.

The 140 kDa ternary complex of insulin-like growth factor-binding protein-3 (IGFBP-3), IGFs and an acid-labile subunit (ALS) has previously been shown to be decreased in diabetes mellitus in humans and rats. We have studied IGF-I levels and ternary complex formation in normal and diabetic cats. Total IGF-I concentrations, measured by RIA using des(1-3)-IGF-I as tracer were (+/-s.e.m.) 54+/-13 nmol/l in eight normal and 227+/-57 nmol/l in eight diabetic cats (P<0.01). The size-distribution of IGFBPs in the cat circulation was determined by incubation with (125)I-IGF-II and Superose 12 chromatography. In normal animals 26+/-2% of the (125)I-IGF-II were in a 140 kDa form compared with 48+/-5% in diabetic cats (P<0.01). When samples from normal and diabetic animals were co-incubated 52+/-3% were at 140 kDa. A similar shift was seen when normal cat and normal human serum were co-incubated. A 2-fold increase in the 140 kDa form in diabetic cats was confirmed first by size-fractionating samples and then performing a ligand-binding assay with (125)I-IGF-I or -II and charcoal separation. SDS-PAGE and Western ligand blotting demonstrated a 45 kDa doublet (presumably IGFBP-3) and 30-35 kDa forms. There were no apparent differences between normal and diabetic profiles on SDS-PAGE, suggesting that a proportion of IGFBP-3 which circulates 'free' in normal cats forms a ternary complex in the diabetic circulation. We conclude that (i) in contrast to humans and rats, ALS is the limiting factor for ternary complex formation in normal cats, (ii) ALS concentrations increase in feline diabetes mellitus and, by promoting ternary complex formation, this leads to an increase in total IGF-I concentrations, and (iii) total IGF-I concentrations may not be reliable in the diagnosis of acromegaly in diabetic cats.

A randomized trial of polyurethane and silicone percutaneous endoscopic gastrostomy catheters.

BACKGROUND: No data are available on differences in complication rate and long-term functioning between polyurethane and silicone percutaneous endoscopic gastrostomy (PEG) catheters. METHODS: We randomized patients who qualified for PEG placement to receive either a polyurethane or silicone PEG catheter. Patients were prospectively monitored for 28 days after placement for the occurrence of complications. Data on long-term PEG survival were obtained retrospectively from the Hospital and general practitioner's medical records. RESULTS: One hundred and six patients were randomized (polyurethane 50, silicone 56). During the first four weeks of follow-up, major complications occurred twice with both polyurethane and silicone PEGs (relative risk 1.1, 95% confidence interval: 0.11-11). Overall complications occurred four times with polyurethane and 17 times with silicone PEGs (relative risk 3.8, 95% confidence interval: 1.37-10.5). Long-term follow-up was available in 96 patients. Seven polyurethane PEGs and 10 silicone PEGs were removed because of PEG malfunctioning, the remainder functioned well until death or the reinstitution of oral feeding. The median complication-free survival was 916 days for the polyurethane PEG and 354 days for the silicone PEG (Log rank test: P=0.24). CONCLUSION: Polyurethane PEG catheters were associated with less short-term complications than silicone catheters, but major complications and long-term function were comparable.

Emission of floral volatiles from Mahonia japonica (Berberidaceae).

Flowering Mahonia japonica plants were subjected to controlled environments and the floral volatiles emitted from whole racemes (laterals) were trapped by Porapak Q adsorbent and analysed by GC-FID. An experiment with photoperiods of 6 and 9 h at constant temperature (10+/-1 degrees C) demonstrated that photoperiod was the stimulus for enhanced emission of most volatiles. Small quantitative differences in emitted fragrance composition were observed between light and dark periods and between plants acclimatised to different photoperiods. Maximum rates of emission occurred in the middle of the light period; aromatic compounds (benzaldehyde, benzyl alcohol and indole) displayed a more rapid increase and subsequent decline compared with monoterpenes (cis- and trans-ocimene and linalool). When the photoperiod was extended from 6 to 9 h, maximum rates of emission continued throughout the additional 3 h. Total emission (microg/h) of volatiles was 2-fold greater in the day-time (DT) (39.7 microg/h) compared with the night-time (NT) (19.8 microgg/h) under a 6 h photoperiod and was not significantly different from total emission under a 9 h photoperiod.

Laboratory evaluation of aqueous humor in the healthy dog, cat, horse, and cow.

Using routinely available clinical laboratory methods, aqueous humor samples were evaluated from 12 healthy dogs, 15 healthy cats, 7 healthy horses, and 6 healthy cows. Aqueous humor was almost acellular; cells that were present had degenerated beyond recognition. Protein concentration was low; only albumin was detectable on electrophoresis. Creatine phosphokinase and lactate dehydrogenase isoenzymes were not detected. Artifacts induced by sampling were insignificant compared with alterations in aqueous humor composition that occur with ocular diseases.