Thermoneutral zone and resting metabolic rate of growing white leghorn‐type chickens

1. Metabolic rate was determined once a week in pullets from commercial flocks of the local White Leghorn strain from the age of 1 d to 13 weeks.

2. The equations relating minimal resting metabolic rate and body weight were: for body weights of 40 to 163 g Y ‐ 1–83 W ^0.986, and for 163 to 1 200 g Y = 11.64 W ^0.623, where Y = O₂ consumption (ml/bird h) and W = body weight (g).

3. The relationship between lower critical temperature (T_d) and age may be described by two equations: for pullets of 1 to 21 d of age Y = 35 ‐ 0.286 X, and for 21 to 70 d of age Y = 63.3 X^{‐ 0.254}, where Y = T _d(°C) and X = age (d).

4. T_d related to body weight is also described by two equations: for body weights of 40 to 163 g Y = ’42 ‐ 1.18 W^0.480 , and for 163 to 800 g r = 42 ‐ 3.60 W^0.260

5. These equations could be used to calculate the T_d on a day‐to‐day basis related to age or body weight.     

Development and validation of instruments measuring body image and body weight dissatisfaction in South African mothers and their daughters

OBJECTIVE: We sought to validate questionnaires concerning body image perception, body size dissatisfaction and weight-related beliefs in multi-ethnic South African mothers and their daughters. SETTINGS AND SUBJECTS: Girls attending primary school (ages 9-12 years, n = 333) and their mothers (n = 204) were interviewed regarding their demographics and body image. Weight, height and skinfold thicknesses were measured. Body image questions and body mass index (BMI) were compared with silhouettes adapted from the Pathways Study for girls and Stunkard's body image figures for mothers. A Feel-Ideal Difference (FID) index score was created by subtracting the score of the silhouette selected by the participants as 'Ideal' from the one selected as most closely representing their current appearance or 'Feel'. We hypothesised that a higher FID index score would be associated with greater body size dissatisfaction. RESULTS: BMI percentiles in girls (r = 0.46, P < 0.05) and BMI in mothers (r = 0.68, P < 0.05) were positively correlated with the selected silhouettes based on size. Participants who reported feelings of being 'fat' and those who perceived that their family and friends were more dissatisfied with their body size had significantly higher FID index scores. Scores were lower in black than white girls (all P<0.05). No differences were found in FID index scores between ethnic groups of mothers. Internal reliability of the 'thin' and 'fat' belief constructs for girls was demonstrated by standardised Cronbach's alpha values > or = 0.7. CONCLUSION: Silhouettes, FID index, 'fat' and 'thin' belief constructs (in girls) are age-appropriate, culturally sensitive and can be used in further intervention studies to understand body image.     

The potential use of fractals in epidemiology

For diseases that are transmitted through parasitic vectors (e.g. tick-borne diseases), the potential distribution and impact of such diseases can be anticipated by studying the distribution of their vectors. Vector distribution is a matter of suitable habitat, which is the sum of a wide range of environmental factors. From remotely sensed data, it is possible to distinguish areas that will provide the most beneficial habitat(s) for a given tick species. The key point is that such data come in the form of patches. The stability of these patches, and therefore that of the tick vectors and the diseases that they transmit, can be mathematically measured using fractal dimensions (D). These fractal dimensions can then be directly related to a non-Markovian (i.e. history dependent) rate of asymptotic decay (H) by using the equation (D=2−H). It is this rate of decay (H) that measures the stability of a given patch(es) of tick habitat(s). If a time series of remotely sensed data is available, changes in the stability (H) can be checked over time. Ultimately, fluctuations of these patches of suitable habitats suggest changes in the tick, and therefore disease, populations. Such fluctuations could destabilize enzootically stable disease populations, or introduce the vectors and diseases into previously naive herds.

As an example of this fractal based measurement of habitat stability, this paper presents empirical evidence of the stability of grass patches in a communal land in Zimbabwe, using data from an aerial photograph. Beyond the practical aspects of measuring the patches, and obtaining their H values, the test data demonstrate that there are at least two distinctive, size based, dynamical systems within the whole set of patches. Generally, patches of a larger size are mathematical less stable than those of a smaller size. The next research objective for the use of such a mathematical tool is to take the concept and apply it on an even larger scale, with the first step undoubtedly being to define what environmental factors constitute suitable habitats for the important tick vector species.     

Comparison of an infrared anaesthetic agent analyser (Datex‐Ohmeda) with refractometry for measurement of isoflurane,sevoflurane and desflurane concentrations

ObjectiveTo assess agreement between infrared (IR) analysers and a refractometer for measurements of isoflurane, sevoflurane and desflurane concentrations and to demonstrate the effect of customized calibration of IR analysers.Study designIn vitro experiment.SubjectsSix IR anaesthetic monitors (Datex-Ohmeda) and a single portable refractometer (Riken).MethodsBoth devices were calibrated following the manufacturer’s recommendations. Gas samples were collected at common gas outlets of anaesthesia machines. A range of agent concentrations was produced by stepwise changes in dial settings: isoflurane (0–5% in 0.5% increments), sevoflurane (0–8% in 1% increments), or desflurane (0–18% in 2% increments). Oxygen flow was 2 L minute^?1. The orders of testing IR analysers, agents and dial settings were randomized. Duplicate measurements were performed at each setting. The entire procedure was repeated 24 hours later. Bland–Altman analysis was performed. Measurements on day-1 were used to yield calibration equations (IR measurements as dependent and refractometry measurements as independent variables), which were used to modify the IR measurements on day-2.ResultsBias ± limits of agreement for isoflurane, sevoflurane and desflurane were 0.2 ± 0.3, 0.1 ± 0.4 and 0.7 ± 0.9 volume%, respectively. There were significant linear relationships between differences and means for all agents. The IR analysers became less accurate at higher gas concentrations. After customized calibration, the bias became almost zero and the limits of agreement became narrower.Conclusions and clinical relevanceIf similar IR analysers are used in research studies, they need to be calibrated against a reference method using the agent in question at multiple calibration points overlapping the range of interest.     

Electrocardiographic evaluation of the degree of sedation and the isolated use of methadone in healthy dogs

ObjectiveThe present study aimed to investigate the influence of methadone on cardiorespiratory parameters, electrocardiogram and clinical sedation in dogs. Further possible side effects are reported.Study designProspective experimental cross-over study.DogsEight, 1–4-year-old, various breeds of dogs of both genders weighing 9–36 kg.MethodsEach dog was treated three times: methadone 0.3 mg kg^?1 (M0.3), 0.5 mg kg^?1 (M0.5) and 1.0 mg kg^?1 (M1.0) intramuscularly. Respiratory rate, heart rate and arterial blood pressure were recorded as well as electrocardiographic evaluation of lead II. Clinical sedation in each treatment received a score (0–3) after drug administration and at 30 minute intervals until scores and measurements returned to baseline values.ResultsA significant decrease in heart rate was seen with each dose of methadone and bradycardia (HR<60 bpm) was noted in a few dogs at each dose. A clinically significant arrhythmia occurred in one dog at 1 mg kg^?1 that required reversal with butorphanol. There was no significant difference in SAP, MAP and DAP between treatments. Some side effects such as salivation, defecation, vocalization and panting, after administration of methadone were observed. There were no differences in mean values of heart rate, P-wave and QRS complex duration and QT interval between treatments.Conclusion and clinical relevanceMethadone administration was associated with panting and a decrease in heart rate at all doses tested in this study. The cardiac rhythm should be monitored carefully in dogs when methadone is administered on its own, especially at higher doses.     

The East-Mediterranean cereal leaf miner <Emphasis Type="Italic">Syringopais temperatella</Emphasis> Lederer and its larval parasitoids in Israel

Leaves of durum wheat infested with mines of the cereal leaf miner Syringopais temperatella Lederer (Lepidoptera: Scythridae) were collected from fields in Israel in spring 2016 and 2017. The parasitoids and moths reared from the leaf mines in the lab were identified and counted according to sex. The sex ratios of S. temperatella were 1:0.73 (♀ :♂) in 2016 and 1:0.41 in 2017. A cross-correlation analysis revealed that males appeared three days ahead of females (p<0.05). The following parasitoids were reared: Eulophidae (Cirrospilus vittatus Walker, Diglyphus chabrias (Walker), D. isaea (Walker), D. sensilis Yefremova, D. pusztensis (Erd?s & Novicky), Necremnus tidius (Walker), Neochrysocharis formosus (Westwood), Pnigalio gyamiensis Myartseva & Kurashev, P. pectinicornis Linnaeus), Pteromalidae (Norbanus sp.) and Braconidae (Habrobracon stabilis (Wesmail), Apanteles sp.); and Icheumonidae (Campoplex sp.). In all cases, the parasitoids emerged substantially prior to the mass appearance of the moths. The hatching dynamics of ecto- and endoparasitoids were also asynchronous. Most species of ectoparasitoids hatched three days ahead of the endoparasitoids (p<0.05). Syringopais temperatella recorded on clover revealed a similar dynamics of male appearance ahead of female, with a of female-to-male ratio of 1:0.25, and fewer parasitoid species.