Efficacy Of Tags Research Articles

Random laser ablated tags for anticounterfeiting purposes and towards physically unclonable functions

Anticounterfeiting tags affixed to products offer a practical solution to combat counterfeiting. To be effective, these tags must be economical, capable of ultrafast production, mass-producible, easy to authenticate, and automatable. We present a universal laser ablation technique that rapidly generates intrinsic, randomly distributed craters (in under a second) on laser-sensitive materials using a nanosecond pulsed infrared laser. The laser and scanning line parameters are balanced to produce randomly distributed craters. The tag patterns demonstrate high randomness, which is analyzed using pattern recognition algorithms and root mean square error deviation. The optical image information of the tag is digitized with a fixed bit uniformity of 0.5 without employing any debiasing algorithm. The efficacy of tags for anticounterfeiting is presented by securing the challenge associated with each tag. Statistical NIST tests are successfully performed on responses generated from both single and multiple tags, demonstrating the true randomness of the sequence of binary digits. The single(multiple) tag(s) achieved an actual encoding capacity of approximately 10391 (10518) and a low false rate (both positive and negative) on the order of 10−58 (10−50). Our findings introduce a laser-based method for anticounterfeiting tag generation, allowing for ultrafast and straightforward product processing with minimal fabrication and tag cost.

99mTc-68Ga-ICG-Labelled Macroaggregates and Nanocolloids of Human Serum Albumin: Synthesis Procedures of a Trimodal Imaging Agent Using Commercial Kits.

Recent developments in sentinel lymph node (SLN) and radio occult lesion localization (ROLL) highlight the need for a multimodal contrast agent, providing better presurgical PET imaging and improved intraoperative mapping thanks to fluorescence detection. For this reason, we have studied a trimodal SLN/ROLL targeting agent (99mTc-68Ga-ICG) with commercially available kits of macroaggregated or nanocolloidal albumin (MA/NC-HSA). 68Ga PET imaging does provide better spatial resolution and makes it possible to predict signal intensity during surgery. The presence of 99mTc assesses the efficacy of these compounds in vitro and also during the surgery procedure. The aim of this study was to optimise the labelling and tagging of these two radiopharmaceuticals and assess their yields and stability. Kits of MA/NC-HSA particles (Pulmocis® and NanoAlbumon®) were used for sequential radiolabelling with 99mTc and 68Ga. Fluorescent tagging was performed using indocyanine green, a tricarbocyanine dye. The ITLC radiochemical purity of the trilabelled MA/NC-HSA was >95%. Fluorescent purity was measured by scanning the strips with a PhotoDynamicEye probe. Finally, in vitro stability tests, performed with DTPA and human serum solutions, assessed the efficacy of fluorescent tagging and radiolabelling.

Computed tomographic colonography with a reduced dose of laxative using a novel barium sulfate contrast agent in Japan.

To test the tagging efficacy, patient acceptability, and accuracy of computed tomographic colonography (CTC) with a reduced dose of laxative using a novel barium sulfate (BaSO4) contrast agent. CTC followed by optical colonoscopy (OC) was performed on 73 patients with positive results in fecal occult blood tests. They were administrated a BaSO4 suspension and a magnesium citrate solution for bowel preparation. Patients completed a questionnaire about the acceptability of bowel preparation. Tagging efficacy was estimated using a novel categorization system, which classified all segments into 8 categories. The accuracy of detecting protruded lesions ≥ 6mm was calculated from the comparison of CTC and OC results, using the latter as a reference standard. Tagging efficacy was good in 77.3% of colonic segments where residue was observed. The acceptability of bowel preparation for CTC was significantly higher than that for OC. The sensitivity, specificity, and positive and negative predictive values were 0.778, 0.945, 0.824, and 0.929, respectively. All lesions ≥ 7mm were successfully detected by CTC. CTC with a reduced dose of laxative using a novel BaSO4 contrast agent has a favorable tagging efficacy, patient acceptability, and accuracy.

Selected Insecticide Delivery Devices for Management of Horn Flies (Haematobia irritans) (Diptera: Muscidae) on Beef Cattle.

The horn fly, Haematobia irritans (L.) (Diptera: Muscidae), is one of the most important pests of the beef cattle industry. Horn fly adults are blood feeders that remain in constant contact with cattle, providing management opportunities via insecticide-impregnated ear tags. Controlling horn flies in the United States is time consuming and costly, but failure to implement management can lead to weight loss and decreased weight gain of calves and yearlings. In the past decade, new chemical combinations have been impregnated into ear tags for pest management. The objectives of this project were to 1) evaluate the efficacy of ear tags against horn fly populations and 2) determine if reduced fly density results in economic return. During 2013, data were compiled by insecticide class; treated cows averaged fly reductions of 198 (s = 38.91; n = 3) for macrocyclic lactone treatments, 175 (s = 62.74; n = 4) for pyrethroid treatments, and 174 (s = 35.28; n = 8) for organophosphate treatments compared with untreated animals (214; s = 50.38; n = 9). During 2014, mean fly reductions were 187 (s = 14.15; n = 4) for macrocyclic lactone, 147 (s = 61.41; n = 13) for pyrethroid, and 143 (s = 77.16; n = 8) for organophosphate treatments relative to the untreated (200; s = 99.83; n = 14). A novel technology, the VetGun application system, tested in 2014, resulted in fly reductions (121 ±, n = 4), but means were not statistically significant from the control (200; s = 99.83; n = 14). Treatment of cattle with ear tags significantly reduced horn fly numbers compared with untreated cattle.

Fecal tag CT colonography with a limited 2-day bowel preparation following incomplete colonoscopy.

This study aimed to assess the feasibility and patient tolerance of a 2-day limited fecal tag bowel preparation in computed tomographic colonography (CTC) performed for incomplete conventional colonoscopy (CC) patients. Seventy-five patients who underwent a CTC examination fbecause of incomplete CC were included. A low-residue diet was given for 2 days before CTC. Fecal tagging (FT) was done using a barium sulfate suspension. The quality of the preparation, success of tagging and patient experience with the bowel preparation were investigated. Four hundred fifty bowel segments were evaluated. The number of solid stool balls of 6-9 mm size was 284; the corresponding figure was 93 for solid stool balls ≥ 10 mm. Residual fluid was present in about one-third of the segments. The fecal tagging efficacy for ≥ 6 mm residual stool balls was 92 %. Overall, 16 (21.3 %) patients presented with colonic lesions at CTC. Three out of four colonic mass lesions had not been diagnosed with CC. Most patients reported mild discomfort. FT-CTC performed after a limited 2-day bowel preparation seems to be a technically feasible, safe and acceptable procedure that allows a complete a colonic study in incomplete CC patients.

Efficacy of slow-release tags impregnated with aggregation-attachment pheromone and deltamethrin for control of Amblyomma variegatum on St. Kitts, West Indies.

BackgroundAmblyomma variegatum is an important cause of morbidity, mortality and economic losses in Africa and the West Indies. Attempts to control and/or eradicate the tick from the Caribbean have largely been unsuccessful because of difficulties relating to the biology of the three-host tick and problems with applying acaricides on a regular basis to free-ranging domestic ruminants. While plastic collars impregnated with insecticides are widely and effectively used in companion animals to control external parasites there is little information on this technology in ruminants.MethodsOver 21 months we tested the efficacy of slow-release plastic tags impregnated with deltamethrin (7%) and aggregation-attachment pheromones (DPITs) in controlling A. variegatum on free-ranging cattle on two farms on St. Kitts. The tags were replaced every three months or when found to be lost.ResultsOn sentinel animals fitted with tags containing only aggregation-attachment pheromones there were an average of 23.1 ticks per semi-monthly visit although this number varied considerably, peaking in the dry season around May and being lowest in August to October during the wet season. Significantly fewer ticks (3.5 on average) were found on cattle with DPITs at each visit (P < 0.001). Although the DIPTs provided good control (92% on average), they did not significantly reduce A. variegatum in the environment with tick numbers on sentinels being higher in the second year of the study, despite up to 44% of animals being fitted with DPITs. The tags were economical, costing 0.2% of the 1% flumethrin pour-on treatment widely recommended for A. variegatum control in the Caribbean. The major problem encountered was that 38% of tail tags were lost before they were due for replacement every three months.ConclusionsOur study has shown that DPITs are cheap to produce, easy to place, only require handling of animals every three months, and are very effective in protecting cattle from A. variegatum. Before DPITs can be considered for eradication programs the problems needing to be addressed include loss of tail tags, particularly in thick vegetation, and the optimum number of animals that must be treated to reduce numbers of ticks in the environment.

Comparative study of efficacy of graft placement with and without anterior tagging in type one tympanoplasty for mucosal-type chronic otitis media

To assess the efficacy of anterior tagging of graft material with respect to graft uptake and hearing results, in type I tympanoplasty. Prospective, randomised, cohort study. Sixty patients with chronic otitis media of the mucosal type, with pars tensa perforations, were included in the study. Patients were randomly allocated to two groups: group one underwent type one tympanoplasty with anterior tagging, while group two underwent type one tympanoplasty without anterior tagging. Follow up included evaluation of graft uptake and hearing improvement. There were 33 patients in group one and 27 patients in group two. The overall incidence of successful graft uptake was 96.96 per cent in group one and 81.5 per cent in group two. Closure of central and posterior perforations was successful in 100 per cent of both groups. Closure of anterior and subtotal perforations was successful in 95.45 per cent of group one and 54.54 per cent of group two. Type one tympanoplasty with anterior tagging of graft material is a suitable technique for anterior and subtotal perforations.

The pitfall with PIT tags: marking freshwater bivalves for translocation induces short-term behavioural costs

Tagging animals is frequently employed in ecological studies to monitor individual behaviour, for example postrelease survival and dispersal of captive-bred animals used in conservation programmes. While the majority of studies focus on the efficacy of tags in facilitating the relocation and identification of individuals, few assess the direct effects of tagging in biasing animal behaviour. We used an experimental approach with a control to differentiate the effects of handling and tagging captive-bred juvenile freshwater pearl mussels, Margaritifera margaritifera , prior to release into the wild. Marking individuals with passive integrated transponder (PIT) tags significantly decreased their burrowing rate and, therefore, increased the time taken to burrow into the substrate. This effect was contributed to, in part, by the detrimental impacts of handling, which also significantly affected activity, burrowing ability and the time taken for each individual to emerge and start probing the substrate. Disturbance during handling and tagging may lead to indirect mortality after release by increasing the risk of predation or dislodgement during flooding, thereby potentially compromising any conservation strategy contingent on population supplementation or reintroduction. This is the first study to demonstrate that handling and PIT tagging has a detrimental impact on invertebrate behaviour. Moreover, our results provide useful information that will inform freshwater bivalve conservation strategies.

디지털 도서관을 위한 소셜 태깅의 의미: 이용자 협력을 활용한 디지털 지식 생성

This study aims to answer whether social tagging through user collaboration could be utilized for the creation of digital knowledge of the web, and whether we could verify the quality and efficacy of social tagging to obtain benefits from it. In particular, this paper examines the inter-indexer consistency of social tagging in comparison to professional indexing. It employs two different similarity measures, both of which are based on the Vector Space Model to deal with numerous indexers. It contributes to the utilization of social tagging in the organization of the web, and encourages to adopt social knowledge in developing suitable vocabularies for resources newly generated in the digital library environment. Furthermore, the comparative analysis with two different measures produced more credible results by illustrating a similar pattern of indexing tendency in both measures.

Efficacy of Internal PIT Tagging of Small-Bodied Crayfish for Ecological Study

Abstract Recent studies have demonstrated the feasibility of using passive integrated transponder (PIT) tags for tracking crayfish spatiotemporally in streams. PIT tags can be inserted internally for long-term tracking, assuming low tagging mortality, or attached externally for shorter-term tracking until the individual molts. To date, the practical use of internal cephalothorax tagging has been limited to individuals >30 mm carapace length (CL). The efficacy of internal tagging for small-bodied crayfish species or juveniles of large-bodied species remains poorly understood. We conducted studies with the small-bodied Orconectes compressus (Slender Crayfish) to assess whether internal placement of small PIT tags (8.5 mm long, 2.12 mm diameter) was a viable methodology for future ecological work. In the field, we tagged 63 crayfish and monitored them with a portable transceiver system for 1.5 weeks. In the laboratory, we tagged 21 crayfish and maintained 21 control crayfish for 12 weeks. Crayfish averaged 1...

Comparison Study of Different Bowel Preparation Regimens and Different Fecal-Tagging Agents on Tagging Efficacy, Patients' Compliance, and Diagnostic Performance of Computed Tomographic Colonography

To compare and find the optimal combination of bowel preparation regimens and different concentrations of barium-based fecal-tagging agents on computed tomographic colonography in terms of tagging efficacy, patients' compliance, and diagnostic performance. Sixty-nine consecutive patients were prospectively enrolled and randomly divided into 4 groups according to a combination of bowel preparation regimens (sodium phosphate [Colclean] vs magnesium citrate [LoSoPrep]) and different concentrations of barium-based fecal-tagging agents (Tagitol V [thick, 40% wt/vol] 60 mL vs EasyCT [thin, 4.6% wt/vol] 600 mL). Patients who received Colclean and EasyCT were designated as group 1; Colclean and Tagitol V as group 2; LoSoPrep and EasyCT, group 3; and LoSoPrep and Tagitol V, group 4. For objective analysis, the volume of tagged feces and fluid was semiautomatically calculated using a threshold of 150 Hounsfield units. The volume of untagged feces and fluid was also calculated using the seeded region-growing method. The tagging efficacy was then calculated and compared using the analysis of variance test. For subjective analysis, 2 radiologists visually determined the overall tagging efficacy on a segmental basis. The numbers of homogeneously tagged, heterogeneously tagged, heterogeneously untagged, and homogeneously untagged feces greater than or equal to 6 mm and fluid were counted in each segment. The rates of homogeneously tagged stool and fluid were compared between the groups using the chi test. Patients' compliance for taking the regimens was recorded and compared using the Kruskal-Wallis test. Per-polyp and per-patient sensitivity for polyps greater than or equal to 6 mm were analyzed and compared using the chi or Fisher exact test. Objective analysis showed that tagging efficacy was significantly lower in group 1 than in the other 3 groups. In a subjective analysis, overall tagging efficacy was significantly higher in group 4 than in the other groups. The rate of homogeneously tagged fluid was significantly higher in group 4 than in the other groups. The rate of homogeneously tagged feces was significantly higher in the thick barium group than in the thin barium group. Patients' compliance was significantly worse in group 1 than in the other 3 groups. Per-polyp and per-patient sensitivities for polyps greater than or equal to 6 mm were not significantly different among all groups. However, per-patient specificity for lesions greater than or equal to 10 mm was significantly lower in group 2 than in the other groups. With better tagging efficacy and compliance while maintaining comparable diagnostic performance, it is our belief that the best combination of bowel preparation and fecal-tagging regimen is a combination of magnesium citrate and a high concentration of a barium tagging agent.

Examining the statistical properties of fine‐scale mapping in large‐scale association studies

Interpretation of dense single nucleotide polymorphism (SNP) follow-up of genome-wide association or linkage scan signals can be facilitated by establishing expectation for the behaviour of primary mapping signals upon fine-mapping, under both null and alternative hypotheses. We examined the inferences that can be made regarding the posterior probability of a real genetic effect and considered different disease-mapping strategies and prior probabilities of association. We investigated the impact of the extent of linkage disequilibrium between the disease SNP and the primary analysis signal and the extent to which the disease gene can be physically localised under these scenarios. We found that large increases in significance (>2 orders of magnitude) appear in the exclusive domain of genuine genetic effects, especially in the follow-up of genome-wide association scans or consensus regions from multiple linkage scans. Fine-mapping significant association signals that reside directly under linkage peaks yield little improvement in an already high posterior probability of a real effect. Following fine-mapping, those signals that increase in significance also demonstrate improved localisation. We found local linkage disequiliptium patterns around the primary analysis signal(s) and tagging efficacy of typed markers to play an important role in determining a suitable interval for fine-mapping. Our findings help inform the interpretation and design of dense SNP-mapping follow-up studies, thus facilitating discrimination between a genuine genetic effect and chance fluctuation (false positive).

CT colonography: optimisation, diagnostic performance and patient acceptability of reduced-laxative regimens using barium-based faecal tagging

To establish the optimum barium-based reduced-laxative tagging regimen prior to CT colonography (CTC). Ninety-five subjects underwent reduced-laxative (13 g senna/18 g magnesium citrate) CTC prior to same-day colonoscopy and were randomised to one of four tagging regimens using 20 ml 40%w/v barium sulphate: regimen A: four doses, B: three doses, C: three doses plus 220 ml 2.1% barium sulphate, or D: three doses plus 15 ml diatriazoate megluamine. Patient experience was assessed immediately after CTC and 1 week later. Two radiologists graded residual stool (1: none/scattered to 4: >50% circumference) and tagging efficacy for stool (1: untagged to 5: 100% tagged) and fluid (1: untagged, 2: layered, 3: tagged), noting the HU of tagged fluid. Preparation was good (76–94% segments graded 1), although best for regimen D (P = 0.02). Across all regimens, stool tagging quality was high (mean 3.7–4.5) and not significantly different among regimens. The HU of layered tagged fluid was higher for regimens C/D than A/B (P = 0.002). Detection of cancer (n = 2), polyps ≥6 mm (n = 21), and ≤5 mm (n = 72) was 100, 81 and 32% respectively, with only four false positives ≥6 mm. Reduced preparation was tolerated better than full endoscopic preparation by 61%. Reduced-laxative CTC with three doses of 20 ml 40% barium sulphate is as effective as more complex regimens, retaining adequate diagnostic accuracy.

Who is tagging information?

AbstractAs Web 2.0 aims to be a more dynamic, interactive, information‐rich environment, social tagging, or the creation of user‐defined metadata by users, (as well as the outcome of tagging, folksonomies or the development of user‐centered vocabularies or lists of keywords that can be used for searching and subject access) (Dye, 2006), is a practice developing to foster online collaboration, independent information sharing and distribution, as well as open communication. Systems that enable social tagging are becoming more common. In the Web 2.0 environment, tagging and folksonomies have been used in different contexts such as photo sharing sites like Flickr, video sharing sites like YouTube, blog search engines like Technorati, and in social bookmarking sites like del.icio.us and LibraryThing (Etches‐Johnson, 2006) . It is generally assumed that more users are learning about and actually tagging resources. Academic articles on tagging are becoming more common (for example, Golder &amp; Huberman, 2005; Marlow, Naaman, Boyd &amp; Davis, 2006). However, little has been reported about tagger's motivations (Abbas, 2007; Abbas &amp; Graham, 2006), the different contexts of tagging, and the the implications for practices and for the library and information science profession (Abbas &amp; Graham, 2006).While the Web 2.0 environment has become a virtual laboratory for exploring the efficacy and utility of social tagging, as well as tagging practices, integrating social tagging into current business and professional practices at different institutions and professions deserves a reality check. The purposes of the panel are: 1) to explore the different contexts in which tagging is being used, 2) to examine how well social tagging has been adopted by several professions such as newspapers, libraries, museums, and within different contexts such as the Web (image and digital video sharing sites), corporations, medical professions, and other information professions, and 3) to discuss implications tagging may have to the library and information science profession. The panelists will present their observations and research results and discuss future trends for different fields.

Collaborative tagging as a knowledge organisation and resource discovery tool

PurposeThe purpose of the paper is to provide an overview of the collaborative tagging phenomenon and explore some of the reasons for its emergence.Design/methodology/approachThe paper reviews the related literature and discusses some of the problems associated with, and the potential of, collaborative tagging approaches for knowledge organisation and general resource discovery. A definition of controlled vocabularies is proposed and used to assess the efficacy of collaborative tagging. An exposition of the collaborative tagging model is provided and a review of the major contributions to the tagging literature is presented.FindingsThere are numerous difficulties with collaborative tagging systems (e.g. low precision, lack of collocation, etc.) that originate from the absence of properties that characterise controlled vocabularies. However, such systems can not be dismissed. Librarians and information professionals have lessons to learn from the interactive and social aspects exemplified by collaborative tagging systems, as well as their success in engaging users with information management. The future co‐existence of controlled vocabularies and collaborative tagging is predicted, with each appropriate for use within distinct information contexts: formal and informal.Research limitations/implicationsLibrarians and information professional researchers should be playing a leading role in research aimed at assessing the efficacy of collaborative tagging in relation to information storage, organisation, and retrieval, and to influence the future development of collaborative tagging systems.Practical implicationsThe paper indicates clear areas where digital libraries and repositories could innovate in order to better engage users with information.Originality/valueAt time of writing there were no literature reviews summarising the main contributions to the collaborative tagging research or debate.

Efficacy of PIT tags and an autonomous antenna system to study the juvenile life stage of an estuarine-dependent fish

Many marine fishes use spatially distinct habitats as juveniles and adults. Determining which juvenile habitats are most important to sustaining adult populations (i.e., which habitats are nurseries) has proven difficult, in part due to challenges in estimating survival of juveniles in putative nursery habitats. Recent technological advances have made large- scale tagging efforts a viable approach to estimating survival of juvenile fishes by increasing recapture rates and enabling the use of individual-identification tags. These techniques, using Passive Integrated Transponder (PIT) tags and autonomous antenna detection systems (antenna), have been successfully applied in freshwater environments. This paper reports the adaptation of these techniques to estuarine mangrove creeks (salinity: 2-28%) for research of the juvenile life stage on an estuarine-dependent marine fish, Centropomus undecimalis. Retention rate of PIT tags in juveniles .120 mm standard length was 100%, with no mortality. The antenna detection field covered 48% of the creek water column, and the antenna was experimentally determined to detect approximately 67% of tagged fish that swam through. Overall recapture rate of tagged fish by the antenna was .40%. This recapture rate is higher than the sparse data typical of traditional tag-recapture studies. A time-dependent Jolly-Seber model was fit to the data, providing estimates of capture probability (0.8) and weekly apparent survival (0.41) that will be invaluable in comparing juvenile habitats of different quality (e.g., natural versus anthropogenically degraded). This research demonstrates the viability of this approach to fish research in estuarine habitats.

CT Colonography After Fecal Tagging with a Reduced Cathartic Cleansing and a Reduced Volume of Barium

The objective of our study was to assess the efficacy of fecal tagging with a small volume of barium in combination with a reduced cathartic cleansing before CT colonography. The study consists of a review of 200 patients examined in a clinical setting. Conventional colonoscopy and CT colonography or follow-up were used as the gold standard. All patients prepared for CT colonography the day before the examination with a dedicated low-residue diet. Fecal tagging was performed with 50 mL of barium. The residual feces and fluid were evaluated on a segmental basis. The residual feces was divided in two categories (< 6 mm and > or = 6 mm). The amount of fluid was assessed on the axial slices. The efficacy of tagging was evaluated visually. For the study, 1,200 segments were evaluated. Residual feces was present in 413 segments (34.41%), with feces less than 6 mm in 210 segments (17.5%) and feces 6 mm or greater in 203 segments (16.92%). There was residual fluid in 527 segments (43.91%). Nontagged feces 6 mm or greater was present in 49 segments (4.08%) and nontagged fluid in 178 segments (14.83%). All nontagged feces 6 mm or greater was easy to assess. All fluid redistributed with dual positioning. A total of 65 lesions 6 mm or greater were correctly diagnosed on primary CT colonography. In two patients, two lesions adjacent to each other were misinterpreted as being only one. Another 8-mm lesion was missed. In the present study, CT colonography after fecal tagging with 50 mL of barium combined with a reduced cathartic cleansing was feasible.

Chlorfenapyr ear tags to control Haematobia irritans (L.) (Diptera: Muscidae) on cattle

The efficacy of ear tags containing 30% chlorfenapyr (total tag weight=13 g) to control natural Haematobia irritans (L.) infestations was evaluated for Holstein heifers in Rafaela, province of Santa Fe, Argentina. A group of heifers (TG) was treated with two ear tags (one tag per ear). A control group (ACG) was maintained in a paddock adjacent to the TG paddock and, a distant control group (DCG) was maintained 700 m apart from the other groups. From day 4 to day 98 after treatment, H. irritans infestations of ACG were significantly higher ( P<0.05, test of Kruskal–Wallis) than the corresponding infestation of TG, but significantly lower than infestation in DCG, probably due to the proximity of TG. The chlorfenapyr control period, with an efficacy higher than 90% to reduce horn fly populations, lasted for 9 weeks when TG infestation was compared to fly numbers in ACG, but increased to 12 weeks in comparison to DCG. The results of this study show that ear tags impregnated with chlorfenapyr are a useful alternative to pyrethroids and organo-phosphate compounds for horn fly control.

Evaluation of insecticide ear tags containing ethion for control of pyrethroid resistant Haematobia irritans (L.) on dairy cattle

A field study was conducted in central Argentina to evaluate the efficacy of ear tags containing 36% ethion against pyrethroid resistant populations of Haematobia irritans on grazing dairy cattle. The treated group consisted of 45 milking Holstein cows which received two tags per head and the control consisted of 22 dry cows from the same cohort. Treated and control groups were grazed on similar lucerne pastures separated for a minimum distance of 800 m but they were not isolated from other cattle herds on the same or contiguous properties. In both groups, horn fly estimation were made weekly by examining cattle in the pastures with the aid of binoculars. The percentage reduction of fly numbers on treated cows was considered as efficacy of control provided by the tags. The ethion ear tags provided a range of 85–99% reduction in horn fly numbers for 16 weeks. During this period, the weekly mean number of H. irritans on the tagged cows ranged between 0.44 and 28.26 compared with 143.5 and 239.1 in control animals. The ethion ear tags could be a useful tool for the control of H. irritans mainly in areas where populations of this insect have developed resistance to pyrethroid insecticides.

Efficacy of tags impregnated with pheromone and acaricide for control of Amblyomma variegatum.

The efficacy of tags impregnated with pheromone and acaricide for control of Amblyomma variegatum on cattle in Guadeloupe was determined for a 13-week trial. Comparisons were made between untreated cattle and cattle with tags containing either pheromones alone (o-nitrophenol, methyl salicylate, 2,6-dichlorophenol and phenylacetaldehyde), pheromones plus acaricide (cyfluthrin or deltamethrin), or acaricide alone. Tags were fastened to cattle both on collars on the neck and with adhesive to tail hairs, with over 98 and 90% of tags retained, respectively, during the trial. By the end of the trial, tick infestations increased on untreated cattle (311.7%) and cattle with pheromone tags (154.8%) but decreased on cattle with pheromone/ cyfluthrin (-45.0%), cyfluthrin (-42.8%), pheromone/deltamethrin (-68.7%) and deltamethrin tags (-87.6%). Cattle with pheromone tags had greater proportions of ticks on the hind regions (81%) compared to untreated cattle (62.5%) and on the front regions (18.2%) compared to untreated cattle (8.2%) indicating that ticks aggregated in response to pheromones. Analysis of hair samples by gas chromatography indicated that, within 2 days of placement, cyfluthrin spread rapidly over the body from the tags. Both cyfluthrin and deltamethrin were present in detectable levels on all eight body regions examined throughout the trial. Analysis of the tags indicated that they all still contained pheromone components after 13 weeks under field conditions.