Regional prestige: Cooperatives and agroindustrial identity in southwest Goiás, Brazil

This study of a wealthy soybeancooperative in central Brazil shows howglobally ambitious institutions promotethemselves as regional organizations. Manystudies of cooperatives focus on their abilityto provide material improvements in the livesof cooperative members and to the locality inwhich they operate. Data from cooperativemembership, from promotional literature, andfrom local news article illustrate symbolicstrategies used by management to aggressivelypromote the idea that the cooperative saved theregion from underdevelopment. The claim that itrepresents regional interests is problematicbecause the cooperative has promoted frontierspeculation by its membership in the Amazon.The cooperative has also embracedexport-oriented agriculture and cattleranching, sidelining regional foodproduction.     

Site factors associated with the performance of Leucaena leucocephala (Lam.) de Wit and Sesbania sesban (L.) Merill in pure and mixed stands in the northern highlands of Rwanda

Alley cropping with leguminous tree hedgerows planted on contours is an emerging practice in the northern highlands of Rwanda where field slopes range from 4 to 76% and loss of soil fertility due to erosion is the principal impediment to food production. Sesbania sesban and Leucaena Leucocephala, the two woody species recommended for alley cropping in the region, do not perform equally well across sites: Sesbania is faster growing, But is more sensitive to pruning than Leucaena. We tested the hypothesis that the two species could be grown together to make the best use of their relative advantages. Species were planted in pure and 1:1 mixed stands at 26 sites to give a range of altitudes, slopes, azimuths and soil fertility levels representative of the region. During two cropping seasons’ growth spanning 19 months, in pure stands, Sesbania produced more biomass, grew taller and had thicker stems than Leucaena: for the same species, stem diameter and height were not different in pure and mixed stands. Biomass and number of poles from 1:1 mixed stands of Sesbania and Leucaena were equivalent to biomass and pole numbers from Sesbania in pure stands. However, mixed stands produced more biomass and pole numbers than Leucaena in pure stands. Growth of S. sesban was positively correlated with soil pH, potassium and altitude; whereas, growth of L. leucocephala was positively correlated with soil phosphorus, but negatively correlated with field slope. All other soil and site variables tested were nonsignificant. The study suggests that farmers can plant S. sesban and L. leucocephala in 1:1 mixtures in an alley cropping setting and retain levels of biomass production and bean pole numbers equivalent to those from S. sesban alone without compromising future growth and production by Leucaena. As well, the impact of pH, K and P on growth and production of Sesbania and Leucaena as a function of field slope and altitude should be determined before extending their use to other regions. This revised version was published online in June 2006 with corrections to the Cover Date.     

Genetic diversity and mating system of <Emphasis Type="Italic">bracatinga</Emphasis> (<Emphasis Type="Italic">Mimosa scabrella</Emphasis>) in a re-emergent agroforestry system in southern Brazil

Bracatinga (Mimosa scabrella) is a legume tree species common in the early stages of succession in Araucaria angustifolia forests in southern Brazil. Bracatinga can form high-density monospecific stands called bracatingais. Its traditional management for charcoal production involves maintenance of the seed bank. Our objective was to analyze the genetic diversity and structure of bracatingais to understand the mechanisms by which intraspecific diversity of M. scabrella is created and maintained in landscapes managed by family farmers in their agroforestry mosaics. We analyzed 14 bracatingais using 8 allozyme loci. We compared parental and progeny generation indices (7 loci) and described the mating system (9 loci) of two progenies. Overall diversity was high: A = 2.69, H _o = 0.257, H _e = 0.382 and similar between populations. Overall fixation (F = 0.364) was similar to the fixation index (f = 0.329). The genetic divergence among populations was low (Θ_p = 0.052) but significant. The progenies’ genetic diversity values were similar to those of the previous generation (H _{e pop11} = 0.342 vs. 0.420/H _{e pop10} = 0.432 vs. 0.400). Progenies were compatible with half-sib and full-sib crossing expectations (θ _xy  = 0.204 and 0.194). Our data showed that there is a tendency for genetic structuring caused not only by the reproductive system but also by genetic drift. It is very likely that the high genetic diversity is amplified by internal migration within each bracatingal. This study showed that current landscape management can contribute to maintaining high levels of bracatinga genetic diversity, which contributes to its regional conservation.     

Among-Provenance Variability of Gas Exchange and Growth in Response to Long-Term Elevated CO2 Exposure

Genetic variability can have profound effects on the interpretation of results from elevated CO₂ studies, and future forest management decisions. Information on which varieties are best suited to future atmospheric conditions is needed to develop future forest management practices. A large-scale screening study of the effects of elevated CO₂ on 15 half-sibling sources of genetically superior ponderosa pine (Pinus ponderosa Dougl ex P. Laws.) is presented. These sources represent multiple elevations and latitudes throughout California. Among-provenance variability in the effects of elevated CO₂ on gas exchange and growth, and their correlation with geographic origin were investigated in ponderosa pine seedlings subjected to ambient or elevated CO₂ concentrations (525 μmol mol^-1 CO₂, and 700 μmol mol^-1 CO₂) for more than two years in open-top chambers. Substantial among-provenance variability in growth response to elevated CO₂ was evident, with 8 sources demonstrating no significant growth response to elevated CO₂ while 7 sources responded positively. For all sources, elevated CO₂ increased photosynthesis (ranging from 19% increase at 525 μmol mol^-1 CO₂ to 49% increase at 700 μmol mol^-1 CO₂). A modest correlation existed between geographic origin and above ground growth response to elevated CO₂.     

The use of Kluyveromyces marxianus in the diet of Red‐Stirling tilapia (Oreochromis niloticus,Linnaeus) exposed to natural climatic variation: effects on growth performance,fatty acids,and protein deposition

The purpose of this study was to evaluate the use of single cell proteins (Kluyveromyces marxianus) as fishmeal substitutes for Oreochromis niloticus during long‐term feeding under natural climatic conditions. Juveniles (150) were divided into two groups: the control group, fed with conventional fish diet (T1); and the experimental group, fed with the alternative diet (T2). T1 animals had a higher final weight and per cent weight gain than T2 animals, which we mainly observed in winter and autumn. The lipid content ranged from 1.9% to 3.8% in liver and from 0.2% to 1% in white muscle for both groups. T2 animals had a higher protein concentration in the fillet and the lipid content in this tissue was not altered by diet. Liver and plasma protein content in both groups and the muscle content in T1 decreased during growth. Specific fatty acids (FAs) were selectively retained in fillet phospholipids (PLs), primarily as C22:6n3, which was found at high levels in the PLs of both groups during all seasons. Despite the differences observed, the percentage of polyunsaturated FAs in the fillet was similar throughout the experiment for both diets, reaching approximately 50% of the total FA in the PLs.     

湖北省水稻技术推广率时空演变及其影响因素研究

通过构建水稻技术推广率评价指标,探究了湖北省1996—2014年不同类型水稻技术相对推广率的时空演变规律,并利用广义最小二乘法(FGLS)实证分析影响湖北省水稻综合技术推广率的主要因素。结果表明:1)湖北省水稻综合技术推广率呈波动上升趋势,化学调控技术相对推广率结构比重最大;2)受育秧栽培技术与化学调控技术相对推广率的共同作用,湖北省水稻综合技术推广率逐步形成"两边高,中间低"的布局。其中,育秧栽培技术相对推广率历经初始的全面提升到近些年大面积回落,最终向鄂西北等山地农业区聚集,而化学调控技术相对推广率偏高区则逐渐向鄂西南等水稻种植规模较大地区聚集;3)农技承包人员有效密度与湖北省水稻综合技术推广率并不存在显著影响关系,种植业产值比重、农村居民人均纯收入、农户经营规模以及分属丘陵平原农业区均对水稻综合技术推广率具有显著正向影响。因此,提出优化农业技术特性、因地制宜开展农技推广工作、完善湖北省农技推广体系和扩大农户经营规模等建议。     

Fatty acid influence on Prochilodus lineatus (Characiformes,Prochilodontidae) embryo cryopreservation parameters.

This study aimed to evaluate the vitellogenic transference and incorporation of long‐chain polyunsaturated fatty acids (LC‐PUFA) into the membranes of Prochilodus lineatus embryos, aiming to increase the permeability to cryoprotectants and resistance to electric fields. One hundred thirty broodstock of P. lineatus were fed with control (C) or fish oil‐supplemented diets (FO) for 12 months. The fatty acid (FA) profle was determined using gas chromatography. For the neutral fraction, the FO group had a decrease in monounsaturated fatty acids (MUFA) and an increase in n3PUFA and, n6PUFA. To test for cryoprotectant toxicity, embryos were exposed for 20 min to a cryoprotectant solution of 1,2‐Propanediol (Prop) at a concentration of 5 or 6 molar (M). For FO, a reduction in survival of 33.1% was observed in 5 M, and no survival was observed at 6 M. Embryo samples were exposed the six polarized electric fields (3.4–51.6 joules), and with 11.2 J of energy, the control group exhibited reduced survival in 98.3% of the fish, whereas the FO presented superior resistance, exhibiting a survival similar to that of the OJ up to 40.2 J. We conclude that FA were transferred between P. lineatus broodstock to the embryos, with an increase in LC‐PUFA resulting in lower survival rates in the cryoprotectant test in the FO group and a greater physical plasticity of FO embryos to electrical field tests.     

What a few hairs can tell us about the resource use of giant armadillos

Understanding of resource requirements of vulnerable species is key for conservation planning. Here, we used stable carbon (δ¹³C) and nitrogen isotopes (δ¹⁵N) of hair from giant armadillos (Priodontes maximus) to understand individual resource use. We collected hair from 19 giant armadillos analyzing 34 samples from the Brazilian Pantanal and compared the resource use between sexes and age classes. We also assessed the relationship of isotopic values with individuals’ body mass and the habitat type used. We observed a wide variation in resource use by giant armadillos, showing that individuals consume prey that feeds on distinct resources and occupies different habitat types, indicating that there is individual variation in foraging behavior. Most giant armadillos presented a mixed diet (C₃/C₄ resources, forests/open areas), but a quarter of individuals had strictly C₄ diets (open areas). Males are more prone to forage on C₄ resources, presenting an isotopic niche 2.6-times larger than that of females. Subadults presented diets more associated with habitats with high arboreal cover (C₃ resources, forests), while adults foraged more in open areas (C₄ resources). This result is mirrored by the positive relationship between δ¹³C values and body mass, suggesting that larger giant armadillos tend to feed more in open areas. We observed that δ¹³C values decreased as individuals increased the use of habitats with high arboreal cover. We stress the importance of conserving the natural mosaic in the Pantanal landscape for the species persistence, given that giant armadillos require all habitat types to fulfill their dietary, spatial, and developmental needs.