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Humpback whales ( Megaptera novaeangliae ) are a cosmopolitan species and perform long annual migrations between low-latitude breeding areas and high-latitude feeding areas. Their breeding populations appear to be spatially and genetically segregated due to long-term, maternally inherited fidelity to natal breeding areas. In the Southern Hemisphere, some humpback whale breeding populations mix in Southern Ocean waters in summer, but very little movement between Pacific and Atlantic waters has been identified to date, suggesting these waters constituted an oceanic boundary between genetically distinct populations. Here, we present new evidence of summer co-occurrence in the West Antarctic Peninsula feeding area of two recovering humpback whale breeding populations from the Atlantic (Brazil) and Pacific (Central and South America). As humpback whale populations recover, observations like this point to the need to revise our perceptions of boundaries between stocks, particularly on high latitude feeding grounds. We suggest that this “Southern Ocean Exchange” may become more frequent as populations recover from commercial whaling and climate change modifies environmental dynamics and humpback whale prey availability.

Arbuscular mycorrhizal (AM) fungi colonize plant roots and often enhance host plant growth and mineral acquisition, particularly for plants grown under low nutrient and mineral stress conditions. Information about AM fungi and mycorrhizal (+AM) host plant responses at low pH (<5) is limited. Acaulospora are widely reported in acid soil, and Gigaspora sp. appear to be more common in acid soils than Glomus sp. Spores of some AM fungi are more tolerant to acid conditions and high Al than others; Acaulospora sp., Gigaspora sp., and Glomus manihotis are particularly tolerant. Root colonization is generally less in low than in high pH soils. Percentage root colonization is generally not related to dry matter (DM) produced. Maximum enhancement of plant growth in acid soil varies with AM fungal isolate and soil pH, indicating adaptation of AM isolates to edaphic conditions. Acquisition of many mineral nutrients other than P and Zn is enhanced by +AM plants in acid soil, and the minerals whose concentration is enhanced are those commonly deficient in acid soils (Ca, Mg, and K). Some AM fungal isolates are effective in overcoming soil acidity factors, especially Al toxicity, that restrict plant growth at low pH.

Endophyte-infected (E+) tall fescue (Festuca arundinacea Schreb.) plants grown in phosphorus (P) deficient soils accumulate more P in roots and shoots than noninfected isolines. In a growth chamber experiment, four tall fescue genotypes DN2, DN4, DN7, and DN11, infected with their naturally occurring strains of Neotyphodium coenophialum (Morgan-Jones & Gams) Glenn, Bacon & Hanlin, and their noninfected isolines (E-), were cultivated in nutrient solution at two P levels: 31 ppm (P+) and 0 ppm (P-) for 4 wk. The Fe³⁺ reducing activity of extracellular reductants and intact root tissues, and total phenolic concentration in roots and shoots were measured. Endophyte infection significantly increased Fe³⁺ reducing activity rate of extracellular reductants (9.6 × 10⁻³ µmol Fe³⁺ h⁻¹g⁻¹ root FW) when compared to E-plants (3.9 × 10⁻³) and Fe³⁺ reduction rate of intact root tissues (6.16 and 4.48 µmol Fe³⁺ h⁻¹ g⁻¹ root FW, respectively for E+ and E- plants). In response to P deficiency, Fe³⁺ reduction rate of intact root tissues increased in E+ plants by 375% when compared to E- plants, whereas no significant differences were observed when P was provided. Total phenolic concentration was 20% greater in shoots of E+ plants than in E- plants. In response to P deficiency, total phenolic concentration significantly increased in roots of E+ plants by 7%, and decreased in roots of E- plants by 10%. The most active Fe³⁺ reducing zones were located along branching of secondary and tertiary roots. The Fe³⁺ reducing activity on the root surface and total phenolic concentration in roots and shoots increased dramatically in response to endophyte infection, especially under P limiting conditions.

Tall fescue (Festuca arundinacea Schreb.) plants infected by the fungal endophyte Neotyphodium coenophialum (Morgan-Jones & Gams) (Glenn et al., 1996) often perform better than noninfected plants, especially in marginal resource environments. There is a lack of information about endophyte related effects on the rhizosphere of grasses. In a greenhouse experiment, four endophyte-infected (E+) tall fescue clones (DN2, DN4, DN7, DN11) and their endophyte-free (E-) forms were grown in limed (pH 6.3) Porter soil (low fertility, acidic, high aluminum and low phosphorus content, coarse-loamy mixed mesic Umbric Dystrochrept) at three soil P levels (17, 50, and 96 mg P kg-1 soil) for five months. Excluding the genotype effect, endophyte infection significantly increased cumulative herbage DM yield by 8% at 17 mg P kg-1 soil but reduced cumulative herbage DM yield by 12% at 96 mg P kg-1 soil. With increased P availability in the soil, shoot and root DM, and root/shoot ratio in E+ plants were significantly less when compared to E- plants. Endophyte infection increased specific root length at 17 and 50 mg P kg-1 soil. At soil P level of 17 mg P kg-1 soil, E+ plants had significantly higher P concentrations both in roots and shoots. Similar relationships were found for Mg and Ca. E+ plants had significantly higher Zn, Fe, and Al concentration in roots, and lower Mn and Al concentration in shoots when compared to E- plants. Ergot alkaloid concentration and content in shoot of E+ plants increased with increasing P availability in the soil from 17 to 50 mg P kg-1 but declined again at 96 mg P kg-1 soil. Ergot alkaloid accumulation in roots increased linearly with P availability in the soil. Results suggest that endophyte infection affects uptake of phosphorus and other mineral nutrients and may benefit tall fescue grown on P-deficient soils. Phosphorus seems also to be involved in ergot alkaloid accumulation in endophyte-infected tall fescue.

A general model for the sorption of trivalent cations to wheat-root (Triticum aestivum L cv. Scout 66) plasma membranes (PM) has been developed and includes the first published coefficients for La3+ and Al3+ binding to a biological membrane. Both ions are rhizotoxic, and the latter ion is the principal contributor to the toxicity of acidic soils around the world. The model takes into account both the electrostatic attraction and the binding of cations to the negatively charged PM surface. Ion binding is modeled as the reaction P- + IZ <==> 'PIZ-1 in which P- represents a negatively charged PM ligand, located in an estimated area of 540 A2, and IZ represents an ion of charge Z. Binding constants for the reaction were assigned for K+ (1 M-1) and Ca2+ (30 M-1) and evaluated experimentally for La3+ (2200 M-1) and H+ (21,500 M-1). Al sorption is complicated by Al3+ hydrolysis that yields hydroxoaluminum species that are also sorbed. Binding constants of 30 and 1 M-1 were assigned for AlOH2+ and Al(OH)+2, respectively, then a constant for Al3+ (20,000 m-1) was evaluated experimentally using the previously obtained values for K+, Ca2+ and H+ binding. Electrostatic attraction was modeled according to Gouy-Chapman theory. Evaluation of parameters was based upon the sorption of ions to PM vesicles suspended in solutions containing variable concentrations of H+, Ca2+ and La3+ or Al3+. Use of small volumes, and improved assay techniques, allowed the measurement of concentration depletions caused by sorption to vesicles. Some independent confirmation of our model is provided by substantial agreement between our computations and two published reports of La3+ effects upon zeta potentials of plant protoplasts. The single published report concerning the electrostatic effects of Al on cell membranes is in essential agreement with the model.

GEORGETOWN, May 7.--Miss Etelka Evans of the Cincinnati Conservatory of Music, who has been touring Texas in the interest of National Music week as a representative of the National Council of Junior Music clubs, of which she is a member, spent several days in Georgetown as the guest of Mrs. Margaret McKennon and Mrs. Ruth Ferguson recently. Miss Evans was formerly dean of music at Southwestern university.

Coal combustion by products (BP) and phosphate rock (PR) have been widely used as cost-effective amendments for acid soils. Information is needed on the proper combination of BP with chemical fertilizers or other organic and inorganic amendments to improve the productivity of acid soils. Chemical analysis and soil incubation studies were carried out to examine the effect of BP, N fertilizers, and zeolite on dissolution of PR and on the status of extractable P in acid soil. Several kinetic models were compared for describing PR dissolution in acid soils that received different amounts of BP, different forms of N fertilizer, and zeolite. PR dissolution in acid soil measured by 0.5 M NaOH extraction was best described by a Langmuir kinetic model (r²=0.988**), followed by an Elovich (r²=0.950**), a two-constant rate (r²=0.947**), a parabolic diffusion (r²=0.905**), and a firstorder reaction equation (r²=0.637*). A second-order reaction equation was the poorest among various models tested (r²=0.484). Addition of BP, N fertilizers, and zeolite to the PR-amended soil did not affect the good fitness of PR dissolution to these kinetic equations. Increasing BP addition decreased initial and average dissolution rate and potential maximum dissolution of PR during the incubation period of 132 days as calculated from the Elovich and Langmuir kinetic models. In general, NH₄NO₃ and (NH₄)₂SO₄ increased the initial rate and decreased slightly the average PR dissolution rate due to a rapid but short-term acidifying effect. On the other hand, urea and zeolite decreased the initial rate of PR dissolution due to higher pH and increased the average PR dissolution rate because of long and persistent acidification by urea and slow but continued removal of Ca by zeolite. The effect of N fertilizers and zeolite on the potential maximum dissolution of PR was related to amounts of BP added. Extractable P in the PR-amended soils as determined by 0.5 M NaHCO₃ was closely correlated with P released by PR dissolution. The ratio of increased NaHCO₃-extractable P due to PR application divided by the total amount of P released from PR dissolution measured by NaOH extraction might reflect relative availability of P from PR dissolution. This ratio was increased by addition of BP, urea, and zeolite but decreased by NH₄NO₃ and (NH₄)₂SO₄.

The study of laboratory animal behavior has increased steadily over the last decade, with expanding emphasis on a variety of commonly used species. In the United States, this trend was initially focused on species for which there was a regulatory requirement to consider normalizing behavior, specifically the U.S. Department of Agriculture’s requirement to promote the psychological well-being of nonhuman primates as reflected in the 1991 Animal Welfare Regulations (AWRs). With the advent of the seventh edition of the Guide (NRC, 1996), more emphasis was placed on addressing the structural, social, and activity elements in all laboratory animals’ cage or pen environments in what was referred to as a ‘behavioral management program.’ The implication that environmental enrichment is a de facto means of normalizing laboratory animal behavior is evidenced by the discussion of this topic as one component of the microenvironment (i.e., cage) for all laboratory species in the eighth edition of the Guide (NRC, 2011). The 2011 Guide also devoted an entire section to ‘Behavioral and Social Management,’ highlighting the importance of motor, cognitive, and social activity; the social environment, noting that single housing of social species should be the exception; and procedural habituation and training of animals.