The role of wax and resin in the nestmate recognition system of a stingless bee, Tetragonisca angustula

Recent research has shown that entrance guards of the stingless bee Tetragonisca angustula make less errors in distinguishing nestmates from non-nestmates than all other bee species studied to date, but how they achieve this is unknown. We performed four experiments to investigate nestmate recognition by entrance guards in T. angustula. We first investigated the effect of colony odours on acceptance. Nestmates that acquired odour from non-nestmate workers were 63% more likely to be rejected while the acceptance rate of non-nestmates treated with nestmate odour increased by only 7%. We further hypothesised that guards standing on the wax entrance tube might use the tube as an odour referent. However, our findings showed that there was no difference in the acceptance of non-nestmates by guards standing on their own colony's entrance tube versus the non-nestmate's entrance tube. Moreover, treatment of bees with nestmate and non-nestmate resin or wax had a negative effect on acceptance rates of up to 65%, regardless of the origin of the wax or resin. The role of resin as a source of recognition cues was further investigated by unidirectionally transferring resin stores between colonies. Acceptance rates of nestmates declined by 37% for hives that donated resin, contrasting with resin donor hives where acceptance of non-nestmates increased by 21%. Overall, our results confirm the accuracy of nestmate recognition in T. angustula and reject the hypothesis that this high level of accuracy is due to the use of the wax entrance tubes as a referent for colony odour. Our findings also suggest that odours directly acquired from resin serve no primary function as nestmate recognition cues. The lack of consistency among colonies plus the complex results of the third and fourth experiments highlight the need for further research on the role of nest materials and cuticular profiles in understanding nestmate recognition in T. angustula.

A morphologically specialized soldier caste improves colony defense in a neotropical eusocial bee

Division of labor among workers is common in insect societies and is thought to be important in their ecological success. In most species, division of labor is based on age (temporal castes), but workers in some ants and termites show morphological specialization for particular tasks (physical castes). Large-headed soldier ants and termites are well-known examples of this specialization. However, until now there has been no equivalent example of physical worker subcastes in social bees or wasps. Here we provide evidence for a physical soldier subcaste in a bee. In the neotropical stingless bee Tetragonisca angustula, nest defense is performed by two groups of guards, one hovering near the nest entrance and the other standing on the wax entrance tube. We show that both types of guards are 30% heavier than foragers and of different shape; foragers have relatively larger heads, whereas guards have larger legs. Low variation within each subcaste results in negligible size overlap between guards and foragers, further indicating that they are distinct physical castes. In addition, workers that remove garbage from the nest are of intermediate size, suggesting that they might represent another unrecognized caste. Guards or soldiers are reared in low but sufficient numbers (1-2% of emerging workers), considering that <1% usually perform this task. When challenged by the obligate robber bee Lestrimelitta limao, an important natural enemy, larger workers were able to fight for longer before being defeated by the much larger robber. This discovery opens up opportunities for the comparative study of physical castes in social insects, including the question of why soldiers appear to be so much rarer in bees than in ants or termites.

Genetic monogamy in the absence of paternity guards: the Capricorn silvereye, Zosterops lateralis chlorocephalus, on Heron Island

We investigated the genetic mating system of a socially monogamous passerine bird, the Capricorn silvereye Zosterops lateralis chlorocephalus, on an island of the Great Barrier Reef. There were no cases of extrapair paternity (EPP) among 122 offspring from 53 broods detectable by minisatellite or microsatellite DNA fingerprinting. Behavioral observations of paired birds showed that this was not a consequence of efficacious paternity guards and that females did not engage in extrapair copulation (EPC). Frequency of intrapair copulations was also low, with only 14 cases observed during 199 hours of observations of the 11 focal pairs in the fertile periods of females, and this was consistent with anatomical features of the cloacal protuberance in males. In this population, young birds form life-time pair bonds soon after gaining independence but females are obviously not attempting EPC possibly to redress this early mate choice. This is despite the fact that they breed in high density with a synchronous start and asynchronous spread of laying in a protracted season and males do not positively exhibit mate guarding behavior when females are fertile. Our results support high fidelity of socially monogamous birds on islands and are consistent with the hypothesis that sexual selection is reduced where genetic variation in fitness is limited.

The guards of the tomb (Matt 27:62–66 and 28:11–15) : Matthew’s apologetic legend revisited

Det har varit vanligt bland forskarna att relativt lite uppmärksamhet fästs vid Matteus berättelse om vakterna vid Jesu grav. Berättelsen har stämplats som en apologetisk legend, skapad av evangelisten eller av en okänd urkristen, mot de judiska ledare som anklagade Kristus-troende för stölden av Jesu kropp. I den här undersökningen utreddes, för det första, om de argument som har framställts när berättelsens möjliga historiska bakgrund har förkastats är hållbara. En närmare analys gav för handen att de inte är det, vilket berättigade en ny fördjupad undersökning av berättelsen. I den andra delen betraktades berättelsen med hjälp av en redaktionskritisk metod. Syftet var att klarlägga om evangelisten har utnyttjat en tradition eller själv skapat historien. Det påvisades att argumenten för det matteiska ursprunget till berättelsen inte är välgrundade i ljuset av en ändamålsenlig statistisk analys. Däremot konstaterades det att flera ord och uttryck var så otypiska för evangelistens allmänna stil att utnyttjandet av en tradition är sannolikt. I den tredje delen av undersökningen analyserades konflikten mellan judar och urkristna, som i denna undersökning kallas Kristus-troende, med hjälp av sådana socialvetenskapliga begrepp som t.ex. symboluniversum och socialt minne, tillsammans med en analys av beskrivningen om konflikten i Apostlagärningar och Pauli brev. Det föreslogs att konflikten utvecklades redan i Jesusrörelsens början i Galileen och eskalerade sedan i Jerusalem resulterande i en antagonistisk attityd mellan Jesu efterföljare och de judiska ledarna i Jerusalem. En kritisk analys av ovannämnda källor visade att antagonismen aktualiserats i flera öppna konflikter under perioden 30-70 eKr. Utifrån frågeställningen i den här undersökningen är det betydelsefullt att en lämplig kontext för den polemiska berättelsen om vakterna vid Jesu grav kan finnas i nästan vilken som helst tidspunkt under perioden. I den fjärde delen var olika teorier beträffande traditionen om Jesu tomma grav betraktade. Att en grupp kvinnor besökte Jesu grav och upptäckte att den var tom påvisades vara det mest sannolika alternativet. I analysen av den egentliga berättelsen om vakterna vid Jesu grav var de vanliga dialogmodellerna kritiskt beskådade och förkastades som för endimensionella. Det föreslogs att stöldanklagelsen var framställd av de judiska ledarna genast efter att Kristus-troendena hade påstått att Jesus är uppstånden. Efter en kritisk evaluering av de olika alternativen visade det sig sannolikt att vakterna blev introducerade till berättelsen av de judiska ledarna. Den kristna berättelsen om vakterna vid graven blev sedan formad reaktivt på grund av denna anklagelse.

Pay roll voucher from the Engineer Department of Port Dalhousie and Thorold Railway Extension for repairs to fences and cattle guards etc. in the months of April and May. This document is attached to a time sheet, May 11, 1857

Pay roll voucher from the Engineer Department of Port Dalhousie and Thorold Railway Extension for repairs to fences and cattle guards etc. in the months of April and May. This document is attached to a time sheet, May 11, 1857.

Bdellovibrio bacteriovorus HD100 guards against Pseudomonas tolaasii brown-blotch lesions on the surface of post-harvest Agaricus bisporus supermarket mushrooms

BACKGROUND: Pseudomonas tolaasii is a problematic pathogen of cultured mushrooms, forming dark brown 'blotches' on mushroom surfaces and causing spoilage during crop growth and post-harvest . Treating P. tolaasii infection is difficult, as other, commensal bacterial species such as Pseudomonas putida are necessary for mushroom growth, so treatments must be relatively specific. RESULTS: We have found that P. tolaasii is susceptible to predation in vitro by the δ-proteobacterium Bdellovibrio bacteriovorus. This effect also occurred in funga, where B. bacteriovorus was administered to post-harvest mushroom caps before and after administration of the P. tolaasii pathogen. A significant, visible improvement in blotch appearance, after incubation, was observed on administration of Bdellovibrio. A significant reduction in viable P. tolaasii cell numbers, recovered from the mushroom tissue, was detected. This was accompanied by a more marked reduction in blotch severity on Bdellovibrio administration. We found that there was in some cases an accompanying overgrowth of presumed-commensal, non-Pseudomonas bacteria on post-harvest mushroom caps after Bdellovibrio-treatment. These bacteria were identified (by 16SrRNA gene sequencing) as Enterobacter species, which were seemingly resistant to predation. We visualised predatory interactions occuring between B. bacteriovorus and P. tolaasii on the post-harvest mushroom cap surface by Scanning Electron Microscopy, seeing predatory invasion of P. tolaasii by B. bacteriovorus in funga. This anti-P. tolaasii effect worked well in post-harvest supermarket mushrooms, thus Bdellovibrio was not affected by any pre-treatment of mushrooms for commercial/consumer purposes. CONCLUSIONS: The soil-dwelling B. bacteriovorus HD100 preys upon and kills P. tolaasii, on mushroom surfaces, and could therefore be applied to prevent spoilage in post-harvest situations where mushrooms are stored and packaged for sale.

Deer Guards and Bump Gates for Excluding White-Tailed Deer From Fenced Resources

White-tailed deer (Odocoileus virginianus) causing damage is a reoccurring theme in the realm of wildlife damage management, especially regarding human safety, disease transmission, and agricultural losses. Fences often are the only reliable long-term nonlethal means of controlling deer damage. The efficacy of fences, however, relies on their weakest link: human-operated gates. Although not overly time-consuming, the act of closing a gate appears to be a burden to individuals, resulting in open-access to an otherwise protected resource. We examined the efficacy of 2 alternatives to traditional gates to evaluate their potential to be used for excluding or containing deer. We evaluated a commercially available kit for mechanically opening and closing gates and a modified deer guard that resembles a common cattle guard but incorporates bearing-mounted rollers as cross members. The gate kit proved effective in restricting deer access to bait throughout the study, but, in supplemental evaluations, we observed excessive rates of functional failure. Deer guards reduced deer entry into exclosures, but efficacy declined with time as deer walked and jumped across guards. With some refining, both guards and gates have potential to be useful components of an integrated biosecurity strategy.

Use of calculus of variations to determine the shape of hovering rotors of minimum power and its application to micro air vehicles

In this paper, calculus of variations and combined blade element and momentum theory (BEMT) are used to demonstrate that, in hover, when neither root nor tip losses are considered; the rotor, which minimizes the total power (MPR), generates an induced velocity that varies linearly along the blade span. The angle of attack of every blade element is constant and equal to its optimum value. The traditional ideal twist (ITR) and optimum (OR) rotors are revisited in the context of this variational framework. Two more optimum rotors are obtained considering root and tip losses, the ORL, and the MPRL. A comparison between these five rotors is presented and discussed. The MPR and MPRL present a remarkable saving of power for low values of both thrust coefficient and maximum aerodynamic efficiency. The result obtained can be exploited to improve the aerodynamic behaviour of rotary wing micro air vehicles (MAV). A comparison with experimental results obtained from the literature is presented.

Design and cost analysis of truck-trailer rear underride guards. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

The Grenadier guards in the great war of 1914-1918,

Mode of access: Internet.

Seymour Vandeleur, the story of a British officer. Being a memoir of Brevet-Lieutenant-Colonel Vandeleur, D.S.O., Scots guards and Irish guards, with a general description of his campaigns,

Each plate accompanied by leaf with descriptive letterpress.

Iron times with the Guards,

Mode of access: Internet.

Final report on hovering breakwaters / c by R.L. Wiegel, H.W. Shen, J.D. Cumming.

Mode of access: Internet.

Proceedings of a general court martial held at the Horse-Guards, on the 24th and 27th of March 1792 : for the trial of Capt. Richard Powell, Lieut. Christopher Seton, and Lieut. John Hall, of the 54th Regiment of Foot, on several charges preferred against them respectively by William Cobbett, late Serjeant-Major of the said regiment; together with several curious letters which passed between the said William Cobbett and Sir Charles Gould, Judge-Advocate General, and various other documents connected therewith in the order of their dates.

308C636no.195 #12.