Exploring the soluble proteome of Tobacco Bright Yellow‐2 cells at the switch towards different cell fates in response to heat shocks

Tobacco (Nicotiana tabacum) Bright Yellow‐2 (TBY‐2) cells undergo different fates when exposed for 10 minutes to heat stresses of different severity. A 35 °C treatment causes a homeostatic response (HRE) allowing cells to cope with the stress; 55 °C triggers processes leading to programmed cell death (PCD), which is complete after 72 h. We have used a proteomic approach to gain insight into the molecular mechanisms defining the fate of TBY‐2 cells induced by these two heat stresses. Tandem mass spectrometry (MS/MS) and two‐dimensional electrophoresis (2‐DE) analysis revealed little overlap of differentially‐accumulated proteins: the different severities of heat treatment induced the modulation of specific proteins, some of which are responsible for different cell fates. When the imposed heat shock is beyond a certain threshold, the overall reduced metabolism may be the result of a series of events involving gene expression and oxidative damage that would lead to PCD. Our data suggest that the down‐accumulation of several proteins involved in cellular redox homeostasis could provide, until now, an unappreciated contribution to understanding how many partners are involved in promoting the redox impairment leading to PCD. Moreover post‐translational modifications seem to play important regulatory roles in the adaptation of TBY‐2 cells to different intensities of heat stress.     

Region-specific assessment of greenhouse gas mitigation with different manure management strategies in four agroecological zones

Livestock farming systems are major sources of trace gases contributing to emissions of the greenhouse gases (GHG) nitrous oxide (N₂O) and methane (CH₄), i.e. N₂O accounts for 10% and CH₄ for 30% of the anthropogenic contributions to net global warming. This paper presents scenario assessments of whole-system effects of technologies for reducing GHG emissions from livestock model farms using slurry-based manure management. Changes in housing and storage practice, mechanical separation, and incineration of the solid fraction derived from separation were evaluated in scenarios for Sweden, Denmark, France, and Italy. The results demonstrated that changes in manure management can induce significant changes in CH₄ and N₂O emissions and carbon sequestration, and that the effect of introducing environmental technologies may vary significantly with livestock farming practice and interact with climatic conditions. Shortening the in-house manure storage time reduced GHG emissions by 0–40%. The largest GHG reductions of 49 to, in one case, 82% were obtained with a combination of slurry separation and incineration, the latter process contributing to a positive GHG balance of the system by substituting fossil fuels. The amount and composition of volatile solids (VS) and nitrogen pools were main drivers in the calculations performed, and requirements to improve the assessment of VS composition and turnover during storage and in the field were identified. Nevertheless, the results clearly showed that GHG emission estimates will be unrealistic, if the assumed manure management or climatic conditions do not properly represent a given country or region. The results also showed that the mitigation potential of specific manure management strategies and technologies varied depending on current management and climatic conditions.     

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.