Multiscale physiological responses to nitrogen supplementation of maize hybrids

Maize (Zea mays) production systems are heavily reliant on the provision of managed inputs such as fertilizers to maximize growth and yield. Hence, the effective use of nitrogen (N) fertilizer is crucial to minimize the associated financial and environmental costs, as well as maximize yield. However, how to effectively utilize N inputs for increased grain yields remains a substantial challenge for maize growers that requires a deeper understanding of the underlying physiological responses to N fertilizer application. We report a multiscale investigation of five field-grown maize hybrids under low or high N supplementation regimes that includes the quantification of phenolic and prenyl-lipid compounds, cellular ultrastructural features, and gene expression traits at three developmental stages of growth. Our results reveal that maize perceives the lack of supplemented N as a stress and, when provided with additional N, will prolong vegetative growth. However, the manifestation of the stress and responses to N supplementation are highly hybrid-specific. Eight genes were differentially expressed in leaves in response to N supplementation in all tested hybrids and at all developmental stages. These genes represent potential biomarkers of N status and include two isoforms of Thiamine Thiazole Synthase involved in vitamin B1 biosynthesis. Our results uncover a detailed view of the physiological responses of maize hybrids to N supplementation in field conditions that provides insight into the interactions between management practices and the genetic diversity within maize.

Predicting career sector intent and the theory of planned behaviour: survey findings from Australian veterinary science students

Background

Producing graduates for a breadth of sectors is a priority for veterinary science programs. Undergraduate career intentions represent de-facto ‘outcome’ measures of admissions policy and curricula design, as intentions are strong predictors of eventual behaviour. Informed by Ajzen’s Theory of Planned Behaviour, this study aimed to identify if contextually relevant attitudes and self-ratings affect student intentions for veterinary career sectors.

Results

Survey responses from 844 students enrolled in five Australian veterinary programs in 2014 were analysed. Intention was measured for biomedical research/academia, industry, laboratory animal medicine, public health/government/diagnostic laboratory services, mixed practice, intensive animal production, companion animal practice, not work in the veterinary profession, and business/entrepreneurship. Hierarchical multiple linear regression analysis enabled comparison of explanation of variance in intent by demographics, animal handling experience, species preference, and attitudes to aspects of veterinary work. Career sector intentions were highest for mixed or companion animal clinical practice, then business/entrepreneurship, then non-clinical sectors. Overall, intent was explained to a greater extent by species preferences than by animal experience, attitudes to aspects of veterinary work and demographics (with the exception of mixed practice intent) with gender having no significant effect. Several variables exerted negative effects on career intent for less popular career sectors.

Conclusion

Ajzen’s Theory of Planned Behaviour (TPB) provides a framework to increase understanding of and predict career sector intentions. Incorporation of attitude and self-efficacy measures in our study revealed preference for species types contributes greatly to career sector intentions for veterinary students, particularly for the more popular practice based sectors. Importantly, specific species preferences and other attitudes can have a negative effect on intent for non-aligned veterinary sectors. Further research is required to identify additional attitudes and/or beliefs to better explain variance in intent for less popular career sectors. Veterinary admissions processes may benefit from utilising the TPB framework. Identified effects revealed by this study may stimulate innovation in marketing, recruitment, admissions and curricular design, such as timing and role modelling, to utilise positive effects and mitigate against negative effects identified for sectors requiring greater representation of career intent in the student body.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1725-4) contains supplementary material, which is available to authorized users.

Cycle-characteristic odour of cow urine can be detected by the female face fly (Musca autumnalis)

Due to declining dairy cow fertility rates, there is great interest in developing tools for oestrus detection. Compounds in the volatile profile of oestrous cows are suggested as oestrus-specific, but consistent results have not been presented. Certain haematophagous arthropods can discriminate stages of the mammalian reproductive cycle based on host volatiles. This study investigated whether the face fly, Musca autumnalis de Geer (Diptera: Muscidae), can discriminate between urine from cows in oestrus and urine collected during the luteal phase. Individual flies were tested in a two-choice behavioural assay with choice between odour of oestrous or luteal urine and water (control). Flies chose the control arm significantly more when exposed to oestrous urine than when exposed to luteal urine. Analysis of volatiles showed that 1-hexadecanol (cetyl alcohol) was released in greater amounts from oestrous urine than from urine collected during the luteal phase. In a dose response assay, flies were significantly attracted by 0.01 ng of 1-hexadecanol but significantly repelled by 0.1 ng, a pattern consistent with fly responses to urine. In conclusion, M. autumnalis can discriminate between oestrous and luteal urine, and this may be mediated by differences in 1-hexadecanol concentration.

THE OCCURRENCE OF ANTIGOITROUS SUBSTANCES IN PLANTS

The development of simple goiter in rabbits, which results when they are fed on a diet consisting chiefly of cabbage (or other Brassica) can be prevented by the feeding of certain fresh plants. Lawn grass, fresh alfalfa, skunk cabbage and steamed cabbage press juice have been found effective. Washing Brassicae with water improves their goiter-producing action, probably by the removal of goiter-preventing substances. The antigoitrous effect of plant juices was found to vary with the amount of reducing substance other than glutathione present. Skunk cabbage press juice, obtained from growing plants during the spring months, contained a large amount of iodine-absorbing material, and was very effective in involuting hyperplastic glands while juice obtained from mature plants in July when the iodine-absorbing material had nearly all disappeared, was quite ineffective. Certain extracts from cabbage administered parenterally, containing the reducing material, also had a marked involuting action on the thyroid. These extracts were practically iodine-free. The substance or substances believed to be responsible are easily soluble in water, ethyl alcohol, aqueous ethyl alcohol and are precipitable by lead acetate at a pH of 0.68–0.70. They are partially destroyed by exposure to air and by steam at 100°. Hexuronic acid isolated by Szent-Györgyi from cabbage, orange juice and suprarenal glands could be the antigoitrous agent. It cannot be glutathione.

THE OCCURRENCE OF SEASONAL VARIATIONS IN THE GOITER OF RABBITS PRODUCED BY FEEDING CABBAGE

The evidence presented indicates that cabbage maturing in the spring and summer months has little goiter-produdag power. Cabbage maturing in the late autumn has much greater goiter-produdng power, although this shows considerable variation in different years. It has not been possible to correlate available meteorological data with these variations.

Rehospitalization following compensable work-related tetraplegia

DESIGN

Descriptive study.

OBJECTIVES

To document the characteristics of rehospitalization following work-related tetraplegia, investigate risk factors for rehospitalization and identify opportunities for rehospitalization prevention.

SETTING

Workers' compensation administrative database with national coverage.

METHODS

The administrative database of a large workers' compensation provider was searched for work-related tetraplegia claims with dates of injury between 1 January 1989 and 31 December 1999. In all, 61 cases were identified where detailed rehospitalization information was available. Medical payment data were extracted, rehospitalization reasons were coded, and rates, costs and length of stay were calculated.

RESULTS

In all, 62% of cases were rehospitalized at some time during the period for which data were available. The average number of days the study group spent rehospitalized per year was 9.2 and the average annual cost was 14,197 US dollars. The most common reasons for rehospitalization were dermatological (23%), orthopedic (18%) and urological (14%). It was found that as many as 74% of the total number of days persons spent rehospitalized, 64% of the monies spent on rehospitalization, and 47% of rehospitalizations could have been prevented.

CONCLUSIONS

Consistent with earlier research, the ability to identify risk factors for rehospitalization was limited. However, the current study does highlight the extent to which rehospitalizations disrupt the lives of people with work-related tetraplegia and that a substantial proportion of rehospitalizations can be avoided.

SPONSORSHIP

The research was supported, in part, by a grant from the National Institute on Disability and Rehabilitation Research National Model SCI Systems (Grant no. H133N00024).

Work-related tetraplegia: cause of injury and annual medical costs

STUDY DESIGN

Descriptive study.

OBJECTIVE

To describe the demographics, cause of injury, and annual-paid medical costs for the 5 years following injury for cases of work-related tetraplegia.

SETTING

A single United States workers' compensation (WC) claims database.

METHODS

Tetraplegia cases with initial date of injury from 1 January 1989 to 31 December 1999 were selected by cross-referencing word search terms pertaining to body part injured and nature of injury. The main outcome measures were injury causes and annual-paid medical payments (adjusted to year 2000 medical consumer price index) of work-related tetraplegia by injury group for each year postinjury over a 5-year time period.

RESULTS

A total of 62 claimants with work-related tetraplegia injured between 1 January 1989 and 31 December 1999. The vast majority of those identified were male claimants (92%) and more than a quarter worked in the construction industry (26%). Other highly represented industries included transportation and retail (15% each), manufacturing (13%), and agriculture and utility (11% each). The majority of injuries were the result of falls (36%) and vehicular accidents (34%). The mean Year 1 cost was US dollars 560524 for those with a high-level tetraplegia (C2-4 ASIA A-C), US dollars 431033 for a low-level injury (C5-8 ASIA A-C), and US dollars 178041 for those with an ASIA D tetraplegia injury. The mean cost of subsequent years (Years 2-5) was US dollars 130992 for a high-level, US dollars 129250 for a low-level, and Us dollars 34352 for an ASIA D tetraplegia injury.

CONCLUSIONS

Mean costs for Year 1 postinjury in WC cases are similar to previously published estimates. Comparing the current results with those of previous spinal cord injury cost studies suggests that those with work-related tetraplegia may receive more injury-related paid medical benefits after the first year postinjury than cases who do not receive WC-supported benefits.

SPONSORSHIP

Supported, in part, by a grant from the National Institute on Disability and Rehabilitation Research (NIDDR) (Grant # H133N00024).

Services provided following compensable work-related tetraplegia

DESIGN

Descriptive study.

OBJECTIVE

To describe and compare the medical services provided following work-related tetraplegic spinal cord injury (SCI).

SETTING

Workers' compensation claims database.

METHODS

The administrative database of a workers' compensation provider was searched for work-related tetraplegia claims with dates of injury between 1 January 1989 and 31 December 1999. In total, 62 cases were identified and grouped by impairment category. Medical payment data were extracted and assigned to service categories.

RESULTS

Although the level of services was directly related to the severity of impairment, patterns were similar across categories; for example, the largest proportions of payments were associated with durable medical equipment (DME) and attendant care in each impairment category. DME, readmissions and attendant care services varied considerably from year to year and within impairment category. Payments for physician care and medications/supplies showed the least variation within impairment categories. Workers' compensation payments were similar to National Spinal Cord Injury Database (NSCID) payments for the first year following injury; however, in subsequent years, workers' compensation figures were much higher.

CONCLUSIONS

Differences in annual medical payment and services by impairment category appear to be primarily due to variations in DME, attendant care and readmission. Payment differences in relation to National SCI figures may be related to better capture of payments by the workers' compensation administrative database. In addition, results suggest broader coverage by workers' compensation for medical services and items related to independent living.

Training to enhance partnerships between mental health professionals and family caregivers: a comparative study

A training program for mental health staff was collaboratively developed and delivered by family caregivers and professionals. It addressed calls for less blaming attitudes toward families and increased contact between professionals and families. Two levels of training were compared. Twenty-seven staff members completed a 30-hour extended 12-week program. Eighty-two percent of all eligible staff from area teams attended a brief program involving three or six hours of training. Self-ratings of competence and attitudes toward families improved only for staff receiving extended training. Contacts with families increased for those in the extended program but not for all types of teams, suggesting that length of training and service type may limit the impact of training.

Karyotype 69,XXX/47,XX,+15 in a 2 1/2 year old child

We present the clinical findings in a 2 1/2 year old girl with an unusual mosaic karyotype. Amniocentesis was performed at 35 weeks because of intrauterine growth retardation. The in situ cultures showed 47,XX,+15 in seven colonies, 69,XXX in four colonies, and in two colonies 46,XX was detected. Subcultures showed 69,XXX/47,XX,+15 with no normal cells. A small dysmorphic baby was born at term. Cytogenetic studies were performed on cord blood, amnion, and placental tissue immediately after birth and further studies on peripheral blood, bone marrow, muscle biopsy, and skin cultures at 1 1/2 years of age. FISH with two autosomal centromeric probes was performed on the peripheral blood sample. A normal cell line could not be seen in any postnatal tissue by either technique. The predominant cell line postnatally was 69,XXX. There were no cytogenetic polymorphisms and the parental origin of the different cell lines was not determined. Marked red cell macrocytosis of peripheral blood was noted on routine blood count. Bone marrow aspiration showed megaloblastic haemopoiesis without evidence of vitamin B12 or folate deficiency. At 2 1/2 years, the patient has significant developmental problems.

A descriptive study of recurrent low back pain claims

This is the first large-scale study of US workers that describes the demographic and cost differences between recurrent and nonrecurrent low back pain (LBP) disability claimants, using data from a large workers' compensation insurer. Persons with at least one LBP claim in 1990 and one or more additional claims in 1990 to 1996 were defined as recurrent. Persons with at least one LBP claim in 1990 but no subsequent claims were defined as nonrecurrent. Fourteen percent of claimants were recurrent. The percentage of recurrent claimants who were male (77.2%) was higher than the percentage that were female (22.8%). This difference was more pronounced in the younger age groups. The median total cost for recurrent LBP claims in 1990 was 4% greater than for nonrecurrent 1990 LBP claims, whereas the mean cost was 48% less. Most studies of LBP recurrence among US workers have followed single-corporation employees. Our rate of recurrence was lower than these previously reported rates. However, analysis of independent workers' compensation insurance company data may provide a more accurate assessment of LBP claim recurrence among US workers.

Homozygous beta-thalassaemia: a review of patients who had splenectomy at the Royal Alexandra Hospital for Children, Sydney

Twenty-four patients with homozygous beta-thalassaemia who had been splenectomised and currently on treatment were studied retrospectively. They were divided into two groups. Group A: who had splenectomy prior to commencement of any regular blood transfusion. The mean haemoglobin for this group rose from 5.5 gm/dl pre-splenectomy to 7.7 gm/dl post splenectomy (p < 0.001). Group B: who were on regular blood transfusion when they had their splenectomy and the mean blood transfusion requirement dropped from 317 ml/kg/yr to 230 ml/kg/yr of packed red cells following splenectomy (p < 0.001). Three patients who were on regular blood transfusion and desferrioxamine developed Yersinia enterocolitica infection. They presented with fever and signs of an acute abdomen. At laparotomy, 2 of the patients had acute appendicitis. All 3 appendices grew Yersinia enterocolitica and one patient also had a Yersinia enterocolitica septicaemia. If a patient develops fever and enteritis, desferrioxamine should be stopped temporarily and cotrimoxazole started as prophylaxis against systemic Yersiniosis. No cases of pneumoccocal sepsis was reported.

Effect of body positions and splints in bioelectrical impedance analysis

The objective of this study was to evaluate body composition as measured by bioelectric impedance analysis using splints and body positions differing from the standard supine position. Forty-three patients, randomized into two groups of different body positions, and 101 healthy volunteers were prospectively studied. Resistance and reactance of body tissues were measured by bioelectric impedance analysis. Body composition is described by a three-compartment model composed of body fat, body cell mass, and extra cellular mass. The patients were measured in the standard supine position and then randomized into two groups. They were then remeasured with the appropriate splinting device or position change. Volunteers were measured in the standard supine position and all four alternative positions. There was a statistically significant difference demonstrated in whole body resistance, whole body reactance, body cell mass, and the ratio of extracellular mass to body cell mass in some body positions. The percentage of change with different body positions and splints, when compared with the standard supine position, was generally below 2%, a clinically insignificant difference. We conclude that the reliability of resistance and reactance as measured by bioelectric impedance analysis is clinically valid using any of the tested body positions and/or splints. The three-compartment model may be a useful concept to measure body composition changes in both healthy and sick persons.

Clinical indicators of dehydration severity in elderly patients

STUDY OBJECTIVE

To determine which of the signs and symptoms of dehydration obtainable from patient history and physical examination in the emergency department are most useful in assessing the severity of dehydration in elderly patients.

DESIGN

Prospective, correlational study.

SETTING

Two university teaching hospitals.

PATIENTS

Fifty-five patients aged 60 or older presenting to the emergency department with suspected dehydration were studied.

MEASUREMENTS AND MAIN RESULTS

In the emergency department, patients were evaluated by a standardized history and physical examination that included assessment of 38 signs and symptoms commonly attributed to dehydration. The relationships between the presence and intensity of these putative dehydration indicators and an independent rating of dehydration severity based on a comprehensive review of the medical record were evaluated. Also evaluated were the relationships between these dehydration indicators and patient age. Indicators that correlated best with dehydration severity but were unrelated to patient age included: tongue dryness (P less than 0.001), longitudinal tongue furrows (P less than 0.001), dryness of the mucous membranes of the mouth (P less than 0.001), upper body muscle weakness (P less than 0.001), confusion (P less than 0.001), speech difficulty (P less than 0.01), and sunkenness of eyes (P less than 0.01). Other indicators had only weak associations with dehydration severity or were also related to age. Patient thirst was unrelated to dehydration severity.

CONCLUSIONS

A set of signs and symptoms related to dehydration severity in elderly patients has been identified. These indicators may be more useful for evaluation of dehydration severity in the emergency department than other commonly used indicators.

BRIEFING: The Planning and Compensation Act 1991: Part II

Considers the sections of Part 1 of the Planning and Compensation Act 1991 which create new, and modify existing, enforcement provisions in the Town and Country Planning Act 1990. Describes planning contravention notices, breach of condition notice, enforcement notices, stop notices, injunctions, rights of entry, certificates of lawful use or development, and compulsory purchase procedures. Concludes that the Act has completed a major reform of the planning system.

BRIEFING: The Planning and Compensation Act 1991

Outlines the provisions of the Planning and Compensation Act 1991, and the implications for property managers and planners. Discusses development plans, definition of development – demolition, applications, appeals, and planning obligations. Summarizes other provisions contained in Part 1 of the Act.

Beta-adrenergic modulation of insulin binding in skeletal muscle

Both a high physiological concentration (13.1 nM) of epinephrine (E) and acute exercise (AEx) have previously been shown to increase 125I-insulin binding in skeletal muscle. To investigate the site and mechanism of the effect of epinephrine on binding and the possible link between epinephrine- and AEx-enhanced insulin binding, we measured insulin binding in three different preparations: 1) crude membranes derived from whole soleus muscle incubated in vitro with 13.1 nM E, 2) crude membranes with E present in the binding assay, and 3) purified plasma membranes with E present. Epinephrine enhanced binding in all three preparations by 169, 144, and 164%, respectively, at low concentrations of insulin but had little effect at high concentrations. Epinephrine, therefore appears to have its effect at the plasma membrane. Propranolol (10 microM), a beta-adrenergic antagonist, blocked E-enhanced insulin binding and when added to crude membranes made from soleus and extensor digitorum longus muscle of AEx rats reversed the increase in binding seen with exercise. This indicates that E-enhanced insulin binding is mediated by beta-adrenergic receptors and that AEx enhances insulin binding via beta-adrenergic receptors. Sodium orthovanadate (3 mM), a phosphotyrosyl-protein phosphatase inhibitor, also inhibited the increase in insulin binding due to E, implying that E may increase insulin binding by activating a phosphotyrosyl-protein phosphatase which decreases the phosphorylation of a plasma membrane protein, presumably the insulin receptor.

Cellular uptake of L-lactate in mouse diaphragm

Early uptake curves of L-lactate and of mannitol were measured in quartered, incubated mouse diaphragms. Uptake was determined at 15, 30, and 45 s for various concentrations of lactate in the external solution as well as in the presence and absence of the competitive inhibitor of lactate transport, alpha-cyano-4-hydroxycinnimate. In normal preparations, when the external lactate concentration was 10 mM or less, the ratio of lactate-to mannitol space in the tissue was 1.7. This value was nearly independent of time and of external concentration. In normal preparations, when the external lactate concentration was greater than 10 mM, the ratio of lactate-to-mannitol space rose with time. At a fixed time, however, this ratio fell with increasing lactate concentration. In the inhibited preparations, the ratio of lactate-to-mannitol space rose with time at all concentrations. When lactate concentration was greater than 5 mM, this ratio was independent of the external concentration. The results suggest that there are two modes of lactate entry into these muscle cells. Entry can occur by means of a saturable system. When external lactate concentration is low, entry rates for this process are rapid compared with diffusional rates. This system probably saturates at concentrations near 10 mM and can facilitate transport in either direction. In addition, an appreciable passive leak is present. This leak accounts for about one fourth of the membrane transfer when external lactate is low, but is equal to the carrier transfer when lactate concentration is 30 mM. A model was developed to describe the entry of a permeating solute, such as lactate, into an isolated tissue.

The assessment and progress of long-stay and elderly psychiatric patients: the predictive validity of a ward behaviour questionnaire

This paper describes an attempt to validate a behaviour rating scale used to predict the likelihood of discharge among elderly and long-stay patients in a psychiatric hospital. The scale measured behaviour on the ward as rated by nursing staff. The scale was a sensitive predictor of discharge among those with a low score (indicating least disability), except for patients with organic psychoses. However, many patients with low scores were not discharged. In order to improve the scale's use as a screening technique additional information was considered. The significance of the findings is discussed.