Further observations on correcting behaviour in boxelder bugs

1. 1. After making a forced turn on a causeway, boxelder bugs make a turn on a platform in a direction opposite to the forced turn. The angle turned on the platform increases abruptly or in sigmoid fashion as the start to forced turn distance increases. Blinded bugs show a similar effect, but the angle is reduced and the increase is not sigmoid or abrupt.2. 2. After running for most of the distance between start and forced turn, bugs can be delayed for 40 seconds or more without effect on mean angle turned on the platform.3. 3. At a certain critical forced turn angle, between 60 [deg] and 75 [deg], the frequency of turns at a choice point offering either a turn opposite to the forced turn or a straight path markedly increases (with the start to forced turn and forced turn to choice point distances kept constant).4. 4. If bugs were made to circle on a causeway, they would turn opposite to the direction of circling upon arrival at a platform. The amount of turn increased as distance run increased or as the radius of the circling arc decreased. Two important factors thus seem to be distance travelled and rate of change of direction.5. 5. Blinding reduces the degree of opposite turning made at a choice point after making an abrupt forced turn and the opposite direction turned on a platform after traversing a circling arc. Opposite turning is, however, still present to some extent. It is the lower halves of the eyes which are important.6. 6. Explanations of the above behaviour based on "centrifugal swing" and "reactive inhibition" are rejected.7. 7. Events occurring at the forced turn probably interact with an excitatory state built up between the start and the forced turn to cause opposite turning at a choice point. Whatever the excitation state, it builds up in sigmoid or abrupt fashion and endures for a period of at least 40 seconds.8. 8. Vision certainly, and proprioception probably, are important factors in the performance of the above behaviour.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32158/1/0000213.pd

An evaluation of global organic aerosol schemes using airborne observations

Chemical transport models have historically struggled to accurately simulate the magnitude and variability of observed organic aerosol (OA), with previous studies demonstrating that models significantly underestimate observed concentrations in the troposphere. In this study, we explore two different model OA schemes within the standard GEOS-Chem chemical transport model and evaluate the simulations against a suite of 15 globally distributed airborne campaigns from 2008 to 2017, primarily in the spring and summer seasons. These include the ATom, KORUS-AQ, GoAmazon, FRAPPE, SEAC4RS, SENEX, DC3, CalNex, OP3, EUCAARI, ARCTAS and ARCPAC campaigns and provide broad coverage over a diverse set of atmospheric composition regimes &ndash; anthropogenic, biogenic, pyrogenic and remote. The schemes include significant differences in their treatment of the primary and secondary components of OA &ndash; a &ldquo;simple scheme&rdquo; that models primary OA (POA) as non-volatile and takes a fixed-yield approach to secondary OA (SOA) formation and a &ldquo;complex scheme&rdquo; that simulates POA as semi-volatile and uses a more sophisticated volatility basis set approach for non-isoprene SOA, with an explicit aqueous uptake mechanism to model isoprene SOA. Despite these substantial differences, both the simple and complex schemes perform comparably across the aggregate dataset in their ability to capture the observed variability (with an R2 of 0.41 and 0.44, respectively). The simple scheme displays greater skill in minimizing the overall model bias (with a normalized mean bias of 0.04 compared to 0.30 for the complex scheme). Across both schemes, the model skill in reproducing observed OA is superior to previous model evaluations and approaches the fidelity of the sulfate simulation within the GEOS-Chem model. However, there are significant differences in model performance across different chemical source regimes, classified here into seven categories. Higher-resolution nested regional simulations indicate that model resolution is an important factor in capturing variability in highly localized campaigns, while also demonstrating the importance of well-constrained emissions inventories and local meteorology, particularly over Asia. Our analysis suggests that a semi-volatile treatment of POA is superior to a non-volatile treatment. It is also likely that the complex scheme parameterization overestimates biogenic SOA at the global scale. While this study identifies factors within the SOA schemes that likely contribute to OA model bias (such as a strong dependency of the bias in the complex scheme on relative humidity and sulfate concentrations), comparisons with the skill of the sulfate aerosol scheme in GEOS-Chem indicate the importance of other drivers of bias, such as emissions, transport and deposition, that are exogenous to the OA chemical scheme. </div

An effect of eyestalk ablation on antennular function in the spiny lobster, Panulirus argus

1. Unilateral removal of the eyestalk (optic ganglia and medulla terminalis) in the Bermuda spiny lobster, Panulirus argus , disrupts normal initiation of feeding activity via chemo-tactile stimulation of the antennule on the side of the ablation. This deficit may be permanent for it has lasted without apparent remission for over five months and two molts. Unilateral eyestalk ablation also produces a temporary increase in antennular cleaning activity directed toward the antennule on the side of the ablation. This effect seems to last for less than 16 days. Unilateral eyestalk ablation does not appreciably disturb spontaneous antennular movements or responses to mechanical stimulation of the antennule on either side. Nor does it destroy the ability of the lobster to give differential responses to mechanical and chemo-tactile stimuli. Most lobsters recover normal sensory and motor functions in antennules that regenerate after amputation of the distal segment and sensory flagellae. In about 1/3 of the animals, however, some form of sensory or motor abnormality is evident in the regenerated antennule. These deficits are ascribed to occasional failure of regenerating neurons to reform appropriate central connections. They do not resemble the deficits following eyestalk ablation. The medulla terminalis is tentatively proposed as the portion of the nervous system critical for normal antennular function that is removed by eyestalk ablation. There seem to be similarities between the effects of eyestalk ablation in the Crustacea as described here and the effects following destruction of portions of the corpora pedunculata in insects. 1. Einseitige Entfernung des Augenstieles (optische Ganglien und Medulla terminalis) bei der Bermuda-Stachellanguste, Panulirus argus , unterbricht auf der operierten Seite den Beginn der normalen Freß-tätigkeit, die durch chemische und taktile Reizung der Antennula eingeleitet wird. Diese Störung kann irreversibel sein, denn sie überdauerte in über 5 Monaten zwei Häutungen.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47096/1/359_2004_Article_BF00340474.pd

Accommodating Dynamic Oceanographic Processes and Pelagic Biodiversity in Marine Conservation Planning

Pelagic ecosystems support a significant and vital component of the ocean's productivity and biodiversity. They are also heavily exploited and, as a result, are the focus of numerous spatial planning initiatives. Over the past decade, there has been increasing enthusiasm for protected areas as a tool for pelagic conservation, however, few have been implemented. Here we demonstrate an approach to plan protected areas that address the physical and biological dynamics typical of the pelagic realm. Specifically, we provide an example of an approach to planning protected areas that integrates pelagic and benthic conservation in the southern Benguela and Agulhas Bank ecosystems off South Africa. Our aim was to represent species of importance to fisheries and species of conservation concern within protected areas. In addition to representation, we ensured that protected areas were designed to consider pelagic dynamics, characterized from time-series data on key oceanographic processes, together with data on the abundance of small pelagic fishes. We found that, to have the highest likelihood of reaching conservation targets, protected area selection should be based on time-specific data rather than data averaged across time. More generally, we argue that innovative methods are needed to conserve ephemeral and dynamic pelagic biodiversity

An experiment on the exchanging of young of the American Robin (Turdus migratorius).

http://deepblue.lib.umich.edu/bitstream/2027.42/51972/1/403.pdfDescription of 403.pdf : Access restricted to on-site users at the U-M Biological Station

Migration : The Biology of Life on the Move

vi,474 hal,;ill,;21 c

A brief ecological study of an open Great Lakes beach.

http://deepblue.lib.umich.edu/bitstream/2027.42/51970/1/401.pdfDescription of 401.pdf : Access restricted to on-site users at the U-M Biological Station