Aluminum-rich apatite

More than 25 atomic percent of aluminum can susbtitute for other cations in the structure of apatite [A(10)(XO(4)) (6)Z(2)]. Such a synthetic product was obtained by expelling volatile constituents (H(2)O and F) from morinite during thermal treatment. Infrared absorption spectra, chemical analysis, and x-ray powder diffraction demonstrate that the aluminum has two coordination numbers, and more than twice as much aluminum substitutes for calcium (A position) as for phosphorus (X position).     

A comparison of the biochemical and physiological effects of the systemic fungicide cyprofuram with those of the related compounds metalaxyl and metolachlor

Strains of Phytophthora megasperma insensitive to the fungicide metalaxyl showed limited cross-resistance to the structurally related fungicide cyprofuram and to metolachlor, a herbicide with antifungal properties. The three compounds each inhibited nucleic acid synthesis, but the wide variation in resistance factors and in the degree of nucleic acid inhibition at the concentrations inhibiting mycelial growth by 50% indicated that cyprofuram and metolachlor possess alternative mechanisms of toxicity. Studies with protoplasts suggested that cyprofuram has a direct effect on the plasma membrane which may be important against those resistant strains where nucleic acid synthesis is least affected. Metolachlor also was extremely effective in causing protoplast lysis. Sporangia production by P. palmivora was stimulated by low concentrations of cyprofuram, and germination was delayed. As with other ‘acylalanine-type’ fungicides, inhibition of nucleic acid synthesis is considered to be the main mode of action. Some degree of cross-resistance between cyprofuram and other acylalanines is likely to occur in the field but the dual mode of action of cyprofuram might delay its onset. The effect of increased sporogenesis on the development of resistance is more difficult to assess.     

Horizontal resistance insolanum tuberosum to colorado potato beetle (leptinotarsa decemlineata say)

Horizontal resistance (HR) was assessed as a strategy to reduce potato defoliation by the Colorado potato beetle (CPB). Hybrids amongSolanum tuberosum varieties grown in Iowa were first evaluated with a detached leaflet feeding bioassay. Beginning in 1998, resistance was increased annually over three years by intermating and selecting the most resistant l%–2% of each generation of 300–400 plants using the bioassay. When C (= mg leaf tissue consumed_* neonate larva^-1 over 48 h) was measured for the 1% most-resistant genotypes of all generations grown side by side in 2000, it ranged from 6.1 mg_* larva^-1 in the parents to 2.3 for progeny of the F₃ generation compared to 2.7 in ND2858-1, a resistant check. Field trials in Wisconsin showed less defoliation in the F₁ and F₂ selected genotypes than in the parents. A second breeding program using moreS. tuberosum parents with greater genetic diversity, and much larger breeding populations, resulted in significantly faster accumulation of resistance, further suggesting that recurrent mass selection is effective. Foliar glycoalkaloid analyses revealed low levels of solanine and chaconine in the F₃ selections; no leptines or leptinines were detected. Because the parents wereS. tuberosum varieties in which vertical resistance to CPB is unknown, and because the resistance to feeding from parents to the F₃ resistant plants was linear and gradual while ranging from initially very low to considerably higher in the third year, horizontal resistance is strongly implicated. The development of a significant degree of resistance after three rounds of breeding using relatively small breeding populations suggests that HR can be developed from varieties ofSolanum tuberosum lacking initial high levels of resistance to CPB.     

Proapoptotic BAX and BAK modulate the unfolded protein response by a direct interaction with IRE1alpha

Accumulation of misfolded protein in the endoplasmic reticulum (ER) triggers an adaptive stress response-termed the unfolded protein response (UPR)-mediated by the ER transmembrane protein kinase and endoribonuclease inositol-requiring enzyme-1alpha (IRE1alpha). We investigated UPR signaling events in mice in the absence of the proapoptotic BCL-2 family members BAX and BAK [double knockout (DKO)]. DKO mice responded abnormally to tunicamycin-induced ER stress in the liver, with extensive tissue damage and decreased expression of the IRE1 substrate X-box-binding protein 1 and its target genes. ER-stressed DKO cells showed deficient IRE1alpha signaling. BAX and BAK formed a protein complex with the cytosolic domain of IRE1alpha that was essential for IRE1alpha activation. Thus, BAX and BAK function at the ER membrane to activate IRE1alpha signaling and to provide a physical link between members of the core apoptotic pathway and the UPR.     

Intercropping teak with Leucaena increases tree growth and modifies soil characteristics

Effects of intercropping Leucaena on early teak growth and soil properties in a simulated taungua system were evaluated in a humid tropical region of central Kerala in peninsular India. The experimental variables included five combinations of teak and Leucaena (100:0, 67:33, 50:50, 33:67, and 0:100). Intercropping Leucaena promoted height and diameter growth of teak. Teak growth increased with increasing relative proportion of Leucaena in the mixture. Forty-four months after planting, teak in the 33% teak-67% Leucaena mixture were 45% taller and 71% larger in diameter at breast height than those in pure stands. Implicit in this growth stimulation of teak by intercropped Leucaena is its nitrogen fixing ability and potential as a soil improver. Soil analysis of the experimental plots provided corroborative evidence in this respect. Total nitrogen increased with increasing relative proportion of Leucaena in the mixture. Available P content of the soil increased as the proportion of Leucaena increased to 50% but declined thereafter. This revised version was published online in June 2006 with corrections to the Cover Date.     

Early maritime economy and El Nino events at quebrada tacahuay, peru

The archaeological site of Quebrada Tacahuay, Peru, dates to 12,700 to 12,500 calibrated years before the present (10,770 to 10,530 carbon-14 years before the present). It contains some of the oldest evidence of maritime-based economic activity in the New World. Recovered materials include a hearth, lithic cutting tools and flakes, and abundant processed marine fauna, primarily seabirds and fish. Sediments below and above the occupation layer were probably generated by El Nino events, indicating that El Nino was active during the Pleistocene as well as during the early and middle Holocene.     

Serum vitamin B12 and methylmalonic acid determinations in the diagnosis of cobalt deficiency in pregnant ewes

Serum vitamin B12 and methylmalonic acid (MMA) concentrations were used to monitor the development of cobalt (Co) deficiency and repletion from the deficient state in housed pregnant hill sheep. Serum MMA concentrations were less variable and provided a more accurate diagnosis of Co deficiency than serum vitamin B12. This was particularly the case for subclinical disease. However, unlike serum MMA, concentrations of the vitamin in serum could be used prognostically. The most precise diagnosis was provided by serum vitamin B12 and MMA data used in conjunction, but where one technique is to be used, serum MMA determinations are preferred.     

Participatory natural resource management in rural China: Making and unmaking environmental narratives

Environmental and development discourses in China can be categorised into three narrative motifs framing human–nature relationships: peasant, indigenous, and community. Indigenous and community narratives have been widely adopted by environmental NGOs (eNGOs) in China in promoting community‐based natural resource management projects, but there has been very limited critical research on such phenomena. Analysis of socio‐economic change in two ethnic minority communities in Yunnan shows that neither narrative theme is fully internalised by the relevant communities. Instead narratives may be strategically modified or even rejected by local communities. This is due to different agendas being held by local communities and eNGOs, and two factors pertinent to rural China: the incompatibility of concepts of ‘community’ in Chinese and international contexts results in confusion, and a lack of recent territorial and cultural claims by rural communities since the collectivist era makes it difficult to construct the identity of a community. It remains challenging for eNGOs in China to advocate either community or indigenous narratives in contexts of rapid socio‐economic change.     

Nitrogen and phosphorus mobilization by the fairy ring fungus, Marasmius oreades (bolt.) fr

Chronological sampling of expanding fairy rings showed that N and P were mobilized during active mycelial extension. Soil through which the fungus had passed exhibited depressed concentrations of extractable N and P. This may be one of a complex of factors which account for the concentric ring life form.