Enthesis: not the same in each localisation - a molecular, histological and biomechanical study.

The interphase between tendon and bone consists of a highly specialised tissue called enthesis. Typically, the enthesis is described as a succession of four different zones: tendon, non-mineralised fibrocartilage, mineralised fibrocartilage and bone. However, the microstructure of the entheses, cellular composition and mechanical properties vary depending on their anatomical location. The present study aimed to characterise three of the most relevant sites of enthesis injury in a rat model: the patellar tendon, the Achilles tendon and the supraspinatus enthesis, in terms of biomechanics, histology and genetic expression. The patellar enthesis presented the highest ultimate load and lowest stiffness of the three, while the supraspinatus was the weakest and stiffest. The histological characterisation revealed key differences at the insertion site for each enthesis. The patellar enthesis showed a large cartilaginous area at the tendon-to-bone interphase whilst this interphase was smaller in the supraspinatus entheses samples. Furthermore, the Achilles tendon enthesis displayed a more abrupt transition from tendon to bone. Additionally, each enthesis exhibited a particular and distinct pattern of expression of tenogenic, chondrogenic and osteogenic markers. This study provided valuable insights for a better understanding of the three entheses at relevant anatomical sites. Moreover, the larger cross-sectional area of the patellar enthesis, the strong mechanical properties and the easier surgical access to this location led to the conclusion that the patellar tendon enthesis site could be most suitable for the development of a preclinical model for general enthesis regeneration studies in rats.

Hematological and biochemical profile of captive brown-throated sloths Bradypus variegatus, Schinz 1825, feeding on ambay pumpwood Cecropia pachystachya Trécul 1847 / [Perfil hematológico e bioquímico da preguiça-de-garganta-marrom Bradypus variegatus, Schinz 1825, em cativeiro alimentando-se de embaúba Cecropia pachystachya Trécul 1847]

The aim of this study was to establish reference parameters for the hematological and biochemical levels of five healthy captive sloths of the speciesBradypus variegatus(brown-throated sloth) feeding onCecropia pachystachya(Ambay pumpwood), alternating with a period of free diet in the Dois Irmãos State Park (DISP) Recife, Pernambuco - Brazil.(AU)

O objetivo da presente pesquisa foi estabelecer parâmetros de referência para níveis hematológicos e bioquímicos, de cinco preguiças sadias, da espécie Bradypus variegatus (preguiça-de-garganta-marrom), em cativeiro, alimentando-se de Cecropia pachystachya (embaúba) em períodos alternados com dieta livre, no Parque Estadual de Dois Irmãos (PEDI) Recife, Pernambuco-Brasil.(AU)

Standardization of 223Ra by live-time anticoincidence counting and gamma-ray emission determination.

From a commercial supplier, three independent lots of an aqueous solution containing 223Ra in equilibrium with its deteriorating progeny were considered for standardization, by using live-time anticoincidence counting (LTAC) in the Laboratório Nacional de Metrologia das Radiações Ionizantes (LNMRI) Brazil. The ionization chamber calibration factors were obtained using measurements of independent lots of 223Ra in LTAC considering the absolute method in order to evaluate the constancy and reproducibility of the standardization. The calibration factors of three high-performance well-type ionization chamber systems and four commercial well-type ionization chambers were determined. The LTAC results showed that lots 2 and 3 were 1069.88 and 1097.44 kBq/kg, with corresponding relative standard uncertainties 0.12% and 0.20%, respectively. The spectrometry method results of each lot value were classified as positive by ANOVA hypothesis testing. The emission probabilities relating to the X- and γ-rays in region from 81 to 830 keV ware determined. Hence, LNMRI can provide calibration services for 223Ra.

Avaliação morfo-histológica e morfo-histométrica de feridas cutâneas tratadas com Sphagneticola trilobata (L) Pruski em ratos / [Morphohistological and morphohistometric evaluation of skin wounds treated with Sphagneticola trilobata (L) Pruski in rats]

O objetivo deste trabalho foi avaliar macro e microscopicamente a atividade cicatrizante da Sphagneticola trilobata em feridas cutâneas induzidas em ratos, a partir da aplicação de creme contendo extrato hidroalcoólico bruto de folhas da planta. A análise fitoquímica apresentou terpenos e flavonoides como compostos majoritários. Sessenta ratos foram divididos em três grupos experimentais (n=20): grupo tratado (GT), grupo controle (GC) e grupo controle absoluto (GCA). Quatro feridas excisionais de 0,8cm de diâmetro foram realizadas no dorso dos animais, tratadas diariamente e avaliadas nos tempos três, sete, 14 e 21 dias de pós-operatório (PO) quanto à contração e à avaliação macroscópica, morfo-histológica e morfo-histométrica. Macroscopicamente, não houve diferença estatística na contração das feridas entre os grupos testados. Na avaliação morfológica e na morfométrica, o GT apresentou menor concentração de células inflamatórias, maior e melhor preenchimento do tecido de granulação pelas fibras colágenas e melhor vascularização das feridas. Não houve diferença entre o GC e o GCA. Conclui-se que o creme à base do extrato hidroalcoólico bruto das folhas de Sphagneticola trilobata contribui positivamente para o processo de cicatrização das feridas em pele de ratos.(AU)

The objective of this work was to macro and microscopically evaluate the healing activity of Sphagneticola trilobata in rat-induced skin wounds by applying cream containing crude hydroalcoholic extract from plant leaves. The phytochemical analysis showed terpenes and flavonoids as major compounds. Sixty rats were divided into three experimental groups (n=20): treated group (GT), control group (CG) and absolute control group (GCA). Four 0.8cm diameter excision wounds were performed on the back of the animals, treated daily and evaluated at the three, seven, 14 and 21 postoperative days (PO) for contraction, macroscopic, morphologic and morphologic evaluation. The TG presented smaller scar area at 21 postoperative days (P<0.05). In the morphological and morphometric evaluation, the WG presented lower inflammation, greater and better filling of granulation tissue by collagen fibers and better wound vascularization. There was no difference between GC and GCA. It was concluded that the cream based on the crude hydroalcoholic extract of Sphagneticola trilobata leaves contribute positively to the healing process of the skin wounds of rats.(AU)

Measurement of the absolute gamma emission intensities from the decay of Th-229 in equilibrium with progeny.

There are few long-lived radionuclides yielding high intensity gamma-rays emission with energies ranging from 100 keV to 500 keV that can be applied as radioactive gamma standard to calibrate HPGe detectors. Furthermore, this energy range represents the main emitted energies of the majority of radionuclides used in nuclear medicine. The Brazilian National Laboratory for Ionizing Radiation Metrology (LNMRI/IRD/CNEN) has attempted to identify radionuclides that have the potential to be used as a calibration source due to their long half-life as well as their emission spectrum. Hence, LNMRI promotes standardization studies of gamma-emitting radionuclides that meet these criteria on order to disseminate them. Thorium-229, with its well-defined energies and relatively high intensities, is one such candidate radionuclide for the energy and full-energy peak efficiency calibration of high-purity gamma spectrometers. Thorium-229 was standardized by the method of 4παß(LS)-γ(NaI(Tl)) live timed anticoincidence counting. The emission intensities of gamma-rays associated with the decay of 229Th have been determined by HPGe gamma ray spectrometry with accuracy and precision. The results are in agreement with current literature data.

Rapid and accurate assessment of the activity measurements in Brazilian hospitals and clinics.

Traceability in Nuclear Medicine Service (NMS) measurements was checked by the Institute of Radioprotection and Dosimetry (IRD) through the Institute of Energy and Nuclear Research (IPEN). In 2016, IRD ran an intercomparison program and invited Brazilian NMS authorized to administer 131I to patients. Sources of 131I were distributed to 33 NMSs. Three other sources from the same solution were sent to IRD, after measurement at IPEN. These sources were calibrated in the IRD reference system. A correction factor of 1.013 was obtained. Ninety percent of the NMS comparisons results are within ±10% of the National Laboratory of Metrology of Ionizing Radiation (LNMRI) value, the Brazilian legal requirement.

134Cs activity standardization by 4πß(LS)-γ(NaI-Tl) anticoincidence counting and submission to international reference system.

From a commercial supplier a solution containing 134Cs has been standardized at National Laboratory for Ionizing Radiation Metrology (LNMRI) for the first time using three Liquid scintillation based measurement. These measurement methods are 4πß-γ live-timed anticoincidence counting, 4πß-γ coincidence counting and 3H-standard efficiency tracing with the CNET methods. The results obtained by anticoincidence counting was adopted as reference value and its combined uncertainty was 0.38%. The agreement of this reference value with coincidence counting and CNET methods were 0.39% and 0.34% respectively and were in consistency with each uncertainty method. The weighted mean results coincidence counting and CNET methods are also in close agreement 0.03% with anticoincidence counting method and meets the requirement of primary and national standard. This standardization was made in order to reduce the uncertainty in 134Cs measurement in Brazil and also following a request made by Bureau International des Poids and Mesures for new submission to International Reference System. The LNMRI last submission was made in 1987. Therefore from a 134Cs master solution a NIST ampoules was prepared and LNMRI/IRD submitted it to the International Reference System, Bureau International of Poids and Measures (SIR/BIPM). In this paper will be analyzed the LNMRI measurement and performance each measurement methods and also take into account the reference value of KCDB, we determined also the 134Cs gamma emission probabilities of main energy.

68(Ge+Ga) activity standardization by 4πß(LS)-γ(NaI(Tl)) anticoincidence counting measurements.

In this work, a 68(Ge+Ga) solution has been standardized at the National Institute of Ionizing Radiation Metrology (LNMRI), in Brazil, in the frame of an international key comparison CCRI(II)-K2.Ge-68 piloted by National Institute of Standards and Technology (NIST/USA). The 4πß(LS)-γ(NaI(Tl)) anticoincidence method with live-time and extended dead-time was used and its result was validated by 4πß(LS)-γ(NaI(Tl)) coincidence counting and liquid scintillation counting using the Triple to Double Coincidence Ratio (TDCR) method. The deviations of the activity concentration values of coincidence and TDCR measurements from the anticoincidence result were 1.7% and 0.63%, respectively, which were within experimental evaluated uncertainties at ~95% level of confidence (coverage factor k = 2). The combined relative standard uncertainties were 0.65%, 0.70% and 0.53% for anticoincidence, coincidence and TDCR methods, respectively. These values are consistent with the results reported by Cessna at the ICRM2017 conference.

Application of the sum-peak method to activity standardizations of 152Eu sources in LNMRI (BR).

The sum-peak method, an absolute measurement technique that uses coincidence counting and γ-ray spectrometry, was applied to activity standardization of 152Eu sources. The decay branch used was that of 152Sm, as it is almost entirely electron capture and exhibits X-rays with a high probability of coincidence with the 121.8keVgamma rays, as evidenced by the matrix technique used for complex decay schemes, a method for deriving counting rate equations describing coincidence summing of gamma and X-rays. The result was compared with the calibration performed by ionization chamber traceable to BIPM. The results presented uncertainty values of 0.50% (k = 1).

Results of an international comparison of activity measurements of 68Ge.

An international key comparison, identifier CCRI(II)-K2.Ge-68, has been performed. The National Institute of Standards and Technology (NIST) served as the pilot laboratory, distributing aliquots of a 68Ge/68Ga solution. Results for the activity concentration, CA, of 68Ge at a reference date of 12h00 UTC 14 November 2014 were submitted by 17 laboratories, encompassing many variants of coincidence methods and liquid-scintillation counting methods. The first use of 4π(Cherenkov)ß-γ coincidence and anticoincidence methods in an international comparison is reported. One participant reported results by secondary methods only. Two results, both utilizing pure liquid-scintillation methods, were identified as outliers. Evaluation using the Power-Moderated Mean method results in a proposed Comparison Reference Value (CRV) of 621.7(11)kBqg-1, based on 14 results. The degrees of equivalence and their associated uncertainties are evaluated for each participant. Several participants submitted 3.6mL ampoules to the BIPM to link the comparison to the International Reference System (SIR) which may lead to the evaluation of a Key Comparison Reference Value and associated degrees of equivalence.

Morphological diversity of cassava accessions of the south-central mesoregion of the State of Mato Grosso, Brazil.

Genetic variability of cassava (Manihot esculenta Crantz) in Brazil is wide, being this the result of natural and cultural selection during pre- and post-domestication of the species in different environments. Given the number of species of the genus found in the region (38 of a total of 98 species), the central region of Brazil was defined as the primary center of cassava diversity. Therefore, genetic diversity characterization of cassava accessions is fundamental, both for farmers and for plant breeders, because it allows the organization of genetic resources and better utilization of available genetic diversity. This research aims to assess genetic divergence of cassava accessions from the south-central region of the State of Mato Grosso, based on multi-categorical morphological traits. For this purpose, 38 qualitative and quantitative morphological descriptors were used. Genetic diversity was expressed by the genetic similarity index, with subsequent clustering of accessions by the modified Tocher's procedure and UPGMA. Of 38 descriptors, only growth habit of stem showed no variability. Tocher and UPGMA methods were efficient and corroborated on group composition. Both methods were able to group accessions of different localities in distinct group consistency.

Standardization of 106Ru/Rh by live-timed anticoincidence counting and gamma emission determination.

The absolute activity standardization measurement system of radionuclide by live-timed anticoincidence counting was implemented at LNMRI in 2008 to reduce the effects of some correction factors on the determination of activity with coincidence counting technique used for decades in the laboratory, for example, the corrections of dead time and resolution. With the live-timed anticoincidence system, the variety of radionuclides that can be calibrated by LNMRI was increased in relation to the type of decay. The objective of this study was to standardize the 106Ru activity, determine gamma emission probabilities by spectrometric method for some energies, and estimate measurement uncertainties.

Proline levels, oxidative metabolism and photosynthetic pigments during in vitro growth and acclimatization of Pitcairnia encholirioides L.B. Sm. (Bromeliaceae).

This study aimed to evaluate the variation in the levels of proline, oxidative metabolism and photosynthetic pigments in plants of Pitcairnia encholirioides grown in vitro under different conditions and after acclimatization. The analyses were performed after 150 days of in vitro cultivation in MS media supplemented with 10 µM GA3 or 0.2 µM NAA, sucrose at 15 or 30 g L-1, in test tubes which allowed gas exchange or in a hermetically sealed system, and 180 days after acclimatization. The in vitro maintenance in hermetically sealed flasks, with GA3 and 15 g L-1 sucrose had adverse metabolic effects, which was demonstrated by the lower proline and photosynthetic pigments accumulation and by the increase in antioxidant enzymes activities. After acclimatization, differences for proline and photosynthetic pigments were no longer found and the enzymatic activities ranged unevenly. The results suggest that the in vitro cultivation in media with 0.2 µM NAA and 30 g L-1 sucrose, in test tubes capped with closures which allowed gas exchange, is more suitable for micropropagation of P. encholirioides, providing a prolonged maintenance of in vitro cultures and plantlets with superior quality for ex vitro development.

Proline levels, oxidative metabolism and photosynthetic pigments during in vitro growth and acclimatization of Pitcairnia encholirioides L.B. Sm. (Bromeliaceae) / Niveis de prolina, do metabolismo oxidativo e dos pigmentos fotossintéticos durante o crescimento in vitro e aclimatização de Pitcairnia encholirioides L.B. Sm. (Bromeliaceae)

Abstract This study aimed to evaluate the variation in the levels of proline, oxidative metabolism and photosynthetic pigments in plants of Pitcairnia encholirioides grown in vitro under different conditions and after acclimatization. The analyses were performed after 150 days of in vitro cultivation in MS media supplemented with 10 µM GA3 or 0.2 µM NAA, sucrose at 15 or 30 g L–1, in test tubes which allowed gas exchange or in a hermetically sealed system, and 180 days after acclimatization. The in vitro maintenance in hermetically sealed flasks, with GA3 and 15 g L–1 sucrose had adverse metabolic effects, which was demonstrated by the lower proline and photosynthetic pigments accumulation and by the increase in antioxidant enzymes activities. After acclimatization, differences for proline and photosynthetic pigments were no longer found and the enzymatic activities ranged unevenly. The results suggest that the in vitro cultivation in media with 0.2 µM NAA and 30 g L–1 sucrose, in test tubes capped with closures which allowed gas exchange, is more suitable for micropropagation of P. encholirioides, providing a prolonged maintenance of in vitro cultures and plantlets with superior quality for ex vitro development.

Resumo Este trabalho objetivou avaliar a contribuição da prolina, do metabolismo oxidativo e dos pigmentos fotossintéticos na propagação in vitro e aclimatização de Pitcairnia encholirioides, uma bromélia criticamente ameaçada de extinção. As análises foram realizadas após 150 dias de cultivo in vitro em meio MS suplementado com 10 µM de GA3 ou 0,2 µM de ANA, 15 ou 30 g L–1 de sacarose, em tubos de ensaio que permitiam trocas gasosas ou em sistema hermeticamente vedado, e também 180 dias após aclimatização. A manutenção in vitro em frascos hermeticamente fechados, com GA3 e 15 g L–1 de sacarose apresentou efeito metabólico adverso, demonstrado pelo menor acúmulo de prolina e pigmentos fotossintéticos e também pelo aumento das atividades de enzimas antioxidantes. Após aclimatização, as diferenças para prolina e pigmentos fotossintéticos não foram mais encontradas e as atividades enzimáticas variaram de maneira desuniforme. Os resultados sugerem que o cultivo in vitro em meio com 0,2 µM de ANA e 30 g L–1 de sacarose, em tubos fechados com tampas que permitem trocas gasosas, é mais adequado para a micropropagação de P. encholirioides, proporcionando uma manutenção prolongada das culturas in vitro e plântulas com qualidade superior para o desenvolvimento ex vitro.

Absolute standardization of the impurity (121)Te associated to the production of the radiopharmaceutical (123)I.

(123)I is widely used for radiodiagnostic procedures. It is produced by reaction of (124)Xe (p,2n) (123)Cs →(123)Xe →(123)I in cyclotrons. (121)Te and (125)I appear in a photon energy spectrum as impurities. An activity of (121)Te was calibrated absolutely by sum-peak method and its photon emitting probability was estimated, whose results were consistent with published results.

Traceability from governmental producers of radiopharmaceuticals in measuring (18)F in Brazil.

Since the inception of its proficiency test program to evaluate radionuclide measurement in hospitals and clinics, the National Metrology Laboratory of Ionizing Radiation-LNMRI, that represents Brazilian National Metrology Institute (NMI) for ionizing radiation has expanded its measurement and calibration capability. Requirements from the National Health Surveillance Agency from Ministry of Health (ANVISA), to producers of radiopharmaceuticals provided an opportunity to improve the full traceability chain to the highest level. Fluorodeoxyglucose (FDG-(18)F) is the only radiopharmaceutical simultaneously produced by all Brazilian radiopharmaceutical production centers (RPCs). By running this proficiency test, LNMRI began to provide them with the required traceability. For evaluation, the ratio of RPC to reference value results and ISO/IEC17043:2010 criteria were used. The reference value established as calibration factor on the secondary standard ionization chamber was obtained from three absolute measurements systems, and routinely confirmed in each round of proficiency test by CIEMAT/NIST liquid scintillation counting. The γ-emitting impurities were checked using a High-Purity Germanium (HPGe) detector. The results show that Brazilian RPCs are in accordance with (accuracy within ±10%) the Brazilian standard for evaluation of measurements with radionuclide calibrators (CNEN NN 3.05., 2013). Nevertheless, the RPCs should improve the methodology of uncertainty estimates, essential when using the statistical criteria of ISO/IEC 17043 standard, in addition to improving accuracy to levels consistent with their position in the national traceability chain.

Hematological markers and biochemical profiles in terms of gender and age of captive collared peccaries (Tayassu tajacu) in eastern Amazon.

Complete blood counts and blood biochemical analyses are laboratory tests that allow the monitoring of physiological condition, nutrition, and health in free-living or captive wild animals. When interpreting these tests, it is essential to compare the results with reference ranges that are suitable for the species. Few studies have been conducted on the hematological and biochemical characteristics of Tayassu tajacu, particularly for animals raised in the Amazon biome. The objectives of this study were to evaluate the influence of age and gender on the hematological and biochemical profiles of captive T. tajacu, and to establish reference intervals for these parameters. Complete blood counts and biochemical analyses were performed using manual methods and semi-automatic equipment, respectively. There were significant differences in relation to age in hematocrit and hemoglobin levels, and mean cell volumes, in captive T. tajacu. No basophils were observed, and the neutrophil:lymphocyte ratio was less than 1. Levels of total protein, urea, phosphorus, and alkaline phosphatase were significantly affected by age (P < 0.05). Gender did not affect any of the results. The hematological and biochemical parameters for this species were determined, and may be used as reference ranges for captive T. tajacu.

Genetic structure of natural populations of Theobroma in the Juruena National Park, Mato Grosso State, Brazil.

Several species within the genus Theobroma have particularly high economic value, including T. cacao and T. grandiflorum. Other species in this genus, such as T. speciosum and T. subincanum, have potential value for use in the conservation of genetic diversity in breeding programs. These latter species could also be domesticated or improved to produce commercial products. Using 13 simple sequence repeat loci, the population structure and genetic diversity of T. speciosum and T. subincanum natural populations in the Juruena National Park, Mato Grosso State, Brazil, was studied. We sampled all individuals of each species (N = 25) present inside a designated research area established by the Program for Research on Biodiversity. The average number of alleles per locus was 5 for T. speciosum and 6.69 for T. subincanum, with average PIC values above 0.5 in both species. All evaluated individuals varied genetically. Seeds from the individuals analyzed will be useful for the development of germplasm banks and for establishment of breeding programs.

Evaluation of the toxic activity of anorectic diethylpropion in Chinese hamster ovary cells.

Diethylpropion has been available in the market for treating obesity for over 50 years. Refined studies are lacking to fully elucidate its action spectrum. The aim of our study was to evaluate possible toxic effects of anorectic diethylpropion in Chinese hamster ovary (CHO) cells. Comet assay (detects breaks in the DNA strand), micronucleus test (detects clastogenic/aneugenic damage), and cell survival test (detects cytotoxic damage) were used to evaluate the toxic effects. In comet assay, we found that the damage scores with diethylpropion treatments at the concentrations of 20 and 40 µg/mL were more significant ( p < 0.05) than that of the negative control. When assessing the possible aneugenic and/or clastogenic damage caused by the drug in CHO cells, we found no difference ( p > 0.05) in the values of micronucleated cells when comparing different diethylpropion treatments and the negative control. Regarding the cell viability, for all the diethylpropion concentrations tested, higher values ( p < 0.05) of apoptosis were found compared with those of the negative control. In relation to the number of necrotic cells, no difference ( p > 0.05) was noted between the means of the three concentrations of diethylpropion evaluated and the negative control. In the experimental conditions, we conclude that diethylpropion has weak genotoxic and cytotoxic activities.

Electronic bolus design impacts on administration.

Electronic identification of animals has become increasingly important worldwide to improve and ensure traceability. In warm and hot climates, such as Brazil, boluses can have advantages over ear tags as the internal devices reduce the risks of ear tag losses, tissue damage, and lesions on the ear. Electronic boluses, however, are often perceived as having negative characteristics, including reported difficulties of administration in small ruminants. This paper describes the factors associated with bolus design that affect the swallowing of a bolus in sheep. Other factors that might influence bolus swallowing time have also been considered. In addition, the effect of bolus design on its performance was evaluated. A total of 56 Suffolk ewes were used to assess the ease of administration and retention of 3 types of electronic ruminal boluses (mini, 11.5 × 58.0 mm and 21.7 g; small, 14.8 × 48.5 mm and 29.5 g; standard, 19.3 × 69.8 mm and 74.4 g) during a whole productive year, including pregnancy and lamb suckling. Ewe age (5.6 ± 2.3 yr) and weight (85.07 ± 8.2 kg BW) were recorded, as well as time for bolus swallowing. The deglutition of the bolus and any resulting blockages in the esophagus were monitored by visual observations. Retention and readability of the boluses were regularly monitored for d 1, wk 1, mo 1, and every mo until 1 yr. Time for bolus swallowing differed substantially with bolus type and was greater (P < 0.05) for the standard bolus (32.8 ± 6.9 s) when compared to small and mini boluses, which did not differ (8.5 ± 2.0 vs. 9.2 ± 2.7 s; P > 0.05). The bolus o.d. and length were positively correlated with swallowing time (P < 0.01). The ewe weight was negatively correlated with swallowing time (P < 0.05). At 6 mo all electronic boluses showed 100% retention rate, and at 12 mo, bolus retention was 100%, 94.5%, and 100% for mini, small, and standard boluses, respectively (P > 0.05). At 12 mo, all boluses showed 100% readability, except for small boluses, which had a readability of 94.5%. In conclusion, bolus design affected swallowing time and bolus readability. A reduction in boluses length and o.d. needs to be carried out to provide ease of administration and for boluses to be used as an effective means of electronic identification. Therefore, this study shows that adequately designed boluses are safe and suitable for identifying adult sheep and can therefore be used in hot climates.