HISTOCHEMICAL STUDIES OF THE EXTRACELLULAR CARBOHYDRATE OF COLACIUM MUCRONATUM (EUGLENOPHYCEAE)1

The stalk of Colacium mucronatum Bourr. & Chad. is composed primarily of a cylindrical shaft with a lightly staining inner core and diffuse peripheral cortex. The shaft and cortex arise from a ring-shaped region around the canal opening whereas the core appears continuous with the canal which may be associated with initial cell attachment. All parts of the stalk, as well as the lining and contents of the reservoir, canal and flagellum exhibit stain reactions associated with neutral or mildly acidic carbohydrate with widely spaced anionic groups in low concentration.     

The expression of Candida albicans enolase is not heat shock inducible

Abstract An isoprotein of enolase from the yeast Saccharomyces cerevisiae was reported to be a heat shock protein. The possible role of the C. albicans enolase as a heat shock protein was therefore investigated. The de novo synthesis of C. albicans enolase protein and mRNA did not increase during heat stress, but remained constitutively expressed. Amino acid similarity to the heat shock proteins suggests that although the C. albicans enolase is not a classical heat shock protein, it may be a memberof a group of constitutively expressed, structurally related proteins, the heat shock cognate proteins.     

Rhythmic oscillations in amygdala excitability during kindling

Unilateral amygdala electrodes were implanted in male Sprague-Dawley rats stimulated once daily with a 200 μamp pulse of 500 millisecond duration to produce kindling. Forty-six percent (12 of 26) of the animals that eventually developed after-discharges demonstrated rhythmic oscillations in after-discharge duration. The presence or absence of generalized bilateral clonic seizures also showed rhythmic oscillations in close association with after-discharge duration. It is suggested that during kindling some animals, independent of electrode placement, develop rhythmic oscillations in excitability of the amygdala. This model may represent a means of experimentally eliciting or uncovering neuronal substrates which show regular alterations in excitability and may be relevant to the oscillations in mood and behavior observed in the affective disorders.     

A survey of nuclear ribosomal internal transcribed spacer substitution rates across angiosperms: an approximate molecular clock with life history effects

Background  

A full understanding of the patterns and processes of biological diversification requires the dating of evolutionary events, yet the fossil record is inadequate for most lineages under study. Alternatively, a molecular clock approach, in which DNA or amino acid substitution rates are calibrated with fossils or geological/climatic events, can provide indirect estimates of clade ages and diversification rates. The utility of this approach depends on the rate constancy of molecular evolution at a genetic locus across time and across lineages. Although the nuclear ribosomal internal transcribed spacer region (nrITS) is increasingly being used to infer clade ages in plants, little is known about the sources or magnitude of variation in its substitution rate. Here, we systematically review the literature to assess substitution rate variation in nrITS among angiosperms, and we evaluate possible correlates of the variation.     

Linking behavioral states to landscape features for improved conservation management

1. A central theme for conservation is understanding how animals differentially use, and are affected by change in, the landscapes they inhabit. However, it has been challenging to develop conservation schemes for habitat‐specific behaviors.
2. Here we use behavioral change point analysis to identify behavioral states of golden eagles (Aquila chrysaetos) in the Sonoran and Mojave Deserts of the southwestern United States, and we identify, for each behavioral state, conservation‐relevant habitat associations.
3. We modeled behavior using 186,859 GPS points from 48 eagles and identified 2,851 distinct segments comprising four behavioral states. Altitude above ground level (AGL) best differentiated behavioral states, with two clusters of short‐distance movement behaviors characterized by low AGL (state 1 AGL = 14 m (median); state 2 AGL = 11 m) and two associated with longer‐distance movement behaviors and characterized by higher AGL (state 3 AGL = 108 m; state 4 AGL = 450 m).
4. Behaviors such as perching and low‐altitude hunting were associated with short‐distance movements in updraft‐poor environments, at higher elevations, and over steeper and more north‐facing terrain. In contrast, medium‐distance movements such as hunting and transiting were over gentle and south‐facing slopes. Long‐distance transiting occurred over the desert habitats that generate the best updraft.
5. This information can guide management of this species, and our approach provides a template for behavior‐specific habitat associations for other species of management concern.