Isolation of the Flagellar Swelling and Identification of Retinal in the Phototactic Flagellate, Ochromonas danica (Chrysophyceae)

Ochromonas danica, a freshwater, planktonic chrysophyte, is capable of sensing the light conditions of its environment. This biflagellate alga has a swelling near the base of the short flagellum and a chloroplastidic stigma in close association with it. A procedure is described for the isolation of this three dimensional flagellar swelling, the presumed photoreceptor. In contrast to an earlier method developed for the isolation of the paraflagellar swelling from Euglena gracilis, the protocol reported here for Ochromonas results in higher yields that should facilitate future biochemical investigations and could open avenues of investigation for the isolation and purification of the presumptive receptor protein. To verify the hypothesis that a rhodopsin-like protein might be present in this alga, we applied a standard extraction procedure successfully used in the identification of retinal. We here report the purification and identification of all-trans retinal in Ochromonas cells by column chromatography, HPLC and GC-MS. Since retinal is the chromophore of rhodopsin-like proteins, this finding may suggest that in these unicellular algae, too, a rhodopsin-like protein could be the photoreceptor pigment.     

Assessing mate size in the red swamp crayfish Procambarus clarkii: effects of visual versus chemical stimuli

1. Mate assessment requires an efficient system of information exchange between the sexes and often relies on several forms of communication. Both sexes of the crayfish, Procambarus clarkii , select a mate on the basis of its body size, independently of chelar size/symmetry and dominance status, large size being a proxy for a high quality partner. Here, we explored the effects that visual and chemical stimuli, emitted alone or in combination, exert on the assessment of size of a potential mate.
2. We followed a binary choice test paradigm, in which two male or female 'targets', of either large or small size, were simultaneously presented to a female or a male 'chooser'. We recorded the first target visited, the total duration of the visits per target, and the behaviour of the chooser when approaching the target area.
3. Our results show that females require a combination of visual and chemical stimuli to select the larger male. A more complex pattern was found when males were the choosers. While visual and chemical cues together rendered them willing to mate with the larger female, their initial choice and the total time spent near her depended only on smell. In mate assessment by P. clarkii , visual and chemical information seem to act as 'non-redundant signals'.     

A Preliminary Assessment of Social and Economic Impacts Associated with Hurricane Katrina

Storm surge and wind associated with Hurricane Katrina caused many deaths and the destruction of property and public infrastructure along the coasts of Louisiana, Mississippi, and Alabama. The devastation was predicted, and absent massive and immediate action, the next major storm will inevitably produce additional disastrous outcomes. Somewhat less predictable are the many social changes associated with the hurricane and public sector response to the event. We characterize some of the more salient human consequences across multiple sectors of the economy—including energy, finance, construction, housing, gaming, and commercial fisheries. We examine how preexisting social trends were amplified, otherwise-latent social and cultural distinctions were exacerbated, and national resources and funds intended for broad-scale "recovery" were converted into instruments of capital formation and further concentration of wealth. We conclude with a discussion exploring public policy and other implications of the disaster in a context of ever-increasing global, environmental, and social challenges.     

Field studies of foraging behaviour of an intertidal beetle

Abstract. 1. Adult staphylinid beetles Thinopinus pictus LeC. are noct turnal predators of sand beach amphipods, Orchestoidea califomiana (Brandt). I made continuous observations of Thinopinus near the drift patches on which amphipods feed.
2. Thinopinus alternated between active and ambush foraging modes.
3. Thinopinus had greater attack rates and captured smaller amphipods while in active foraging mode.
4. Thinopinus attacked 0.147 amphipods/min, and captured 9.1% of the amphipods attacked. The attack rate on amphipods increased with the proportion of time spent by Thinopinus in active mode.
5. Thinopinus remained longer near types of drift patches which were more attractive to amphipods.     

Curative Effects of the Antipiroplasms Amicarbalide and Imidocarb on Trypanosoma brucei Infection in Mice*

SYNOPSIS The babesicides imidocarb and amicarbalide, which have structural similarities to the antitrypanosomatid diamidines, proved active against Trypanosoma brucei mouse infections: both cured infections when doses were administered daily for 3 days 24 h post-inoculation (curative dose imidocarb, 10 mg/kg; amicarbalide, 25 mg/kg). Mice were considered cured after survival 30 days longer than untreated infected controls, with no trypanosomes present in blood or cerebrospinal fluid smears. Both agents also cured when administered 48 and 72 h after challenge with T. brucei and prolonged the lives of animals 94 h after challenge. The results are discussed in respect to the potential of these carbanilides and their precursors, the antitumor phthalanilides, as lead compounds in chemotherapy of mammalian trypanosomiases.     

DETAINED AND DRUGGED: A BRIEF OVERVIEW OF THE USE OF PHARMACEUTICALS FOR THE INTERROGATION OF SUSPECTS, PRISONERS, PATIENTS, AND POWS IN THE US

Using medical literature citations, Congressional hearings, and declassified documents this paper examines the uses of pharmaceuticals in the interrogation of vulnerable populations. From the use of IV relaxants on criminal suspects during the 1920s to the Global War on Terror, the nexus of drugs, testing, and interrogations will be explored in both the domestic and international contexts.     

A key for the identification of the known larval stages of the Mediterranean Brachyura

Summary

Based on the accounts by various authors, an identification key has been constructed for the planktonic zoeae of the 70 species of Mediterranean Brachyura whose larvae are known. The key is based on primary (spines of the carapace, exopodite of the antenna, spines of telson forks) as well as secondary (setation of mouthparts, processes and spines on abdominal somites) morphological characteristics. It allows the identification of the zoeae of 64 species plus those of Liocarcinus genus (six species).     

A LEAFCUTTER BEE TRACE FOSSIL FROM THE MIDDLE EOCENE OF PATAGONIA, ARGENTINA, AND A REVIEW OF MEGACHILID (HYMENOPTERA) ICHNOLOGY

Abstract:  The ichnospecies Phagophytichnus pseudocircus isp. nov. is described to include trace fossils characterized by leaf-margin excisions showing eccentricity values of 0.35–0.65 and more than 270 degrees of an arc, a non cuspate margin and vein stringers or necrotic flaps of tissue along the margin. A method for determining ellipse eccentricity was performed on leaf discs obtained from the nests of the modern leafcutter bee Megachile rotundata (Hymenoptera: Megachilidae), which provided objectively obtained values comparable to the trace fossil from the middle Eocene of Argentina and other world-wide ichnological records, historically and subjectively considered to be 'circular' trace fossils and attributed to leafcutter bees. The material described herein represents the first evidence for fossil Megachilidae from the Southern Hemisphere.