A high-resolution radiation hybrid map of the human genome draft sequence

We have constructed a physical map of the human genome by using a panel of 90 whole-genome radiation hybrids (the TNG panel) in conjunction with 40,322 sequence-tagged sites (STSs) derived from random genomic sequences as well as expressed sequences. Of 36,678 STSs on the TNG radiation hybrid map, only 3604 (9.8%) were absent from the unassembled draft sequence of the human genome. Of 20,030 STSs ordered on the TNG map as well as the assembled human genome draft sequence and the Celera assembled human genome sequence, 36% of the STSs had a discrepant order between the working draft sequence and the Celera sequence. The TNG map order was identical to one of the two sequence orders in 60% of these discrepant cases.     

Nutrient limitations to bacterial and fungal growth during cellulose decomposition in tropical forest soils

Nutrients constrain the soil carbon cycle in tropical forests, but we lack knowledge on how these constraints vary within the soil microbial community. Here, we used in situ fertilization in a montane tropical forest and in two lowland tropical forests on contrasting soil types to test the principal hypothesis that there are different nutrient constraints to different groups of microorganisms during the decomposition of cellulose. We also tested the hypotheses that decomposers shift from nitrogen to phosphorus constraints from montane to lowland forests, respectively, and are further constrained by potassium and sodium deficiency in the western Amazon. Cellulose and nutrients (nitrogen, phosphorus, potassium, sodium, and combined) were added to soils in situ, and microbial growth on cellulose (phospholipid fatty acids and ergosterol) and respiration were measured. Microbial growth on cellulose after single nutrient additions was highest following nitrogen addition for fungi, suggesting nitrogen as the primary limiting nutrient for cellulose decomposition. This was observed at all sites, with no clear shift in nutrient constraints to decomposition between lowland and montane sites. We also observed positive respiration and fungal growth responses to sodium and potassium addition at one of the lowland sites. However, when phosphorus was added, and especially when added in combination with other nutrients, bacterial growth was highest, suggesting that bacteria out-compete fungi for nitrogen where phosphorus is abundant. In summary, nitrogen constrains fungal growth and cellulose decomposition in both lowland and montane tropical forest soils, but additional nutrients may also be of critical importance in determining the balance between fungal and bacterial decomposition of cellulose.     

Single-cell mass cytometry of differential immune and drug responses across a human hematopoietic continuum

Flow cytometry is an essential tool for dissecting the functional complexity of hematopoiesis. We used single-cell "mass cytometry" to examine healthy human bone marrow, measuring 34 parameters simultaneously in single cells (binding of 31 antibodies, viability, DNA content, and relative cell size). The signaling behavior of cell subsets spanning a defined hematopoietic hierarchy was monitored with 18 simultaneous markers of functional signaling states perturbed by a set of ex vivo stimuli and inhibitors. The data set allowed for an algorithmically driven assembly of related cell types defined by surface antigen expression, providing a superimposable map of cell signaling responses in combination with drug inhibition. Visualized in this manner, the analysis revealed previously unappreciated instances of both precise signaling responses that were bounded within conventionally defined cell subsets and more continuous phosphorylation responses that crossed cell population boundaries in unexpected manners yet tracked closely with cellular phenotype. Collectively, such single-cell analyses provide system-wide views of immune signaling in healthy human hematopoiesis, against which drug action and disease can be compared for mechanistic studies and pharmacologic intervention.     

Tepary beans (Phaseolus acutifolius var. latifolius): a potential food source for African and Middle Eastern cultures

Tepary bean (Phaseolus acutifolius var. latifolius), a native North American legume adapted to arid/semiarid lands was partially evaluated as a potential food source for people of African and Middle Eastern regions. To indicate the acceptability of these pulses, traditional Nigerian and Saudi Arabian foodstuffs were formulated with teparies substituted for beans commonly used in these regions. Organoleptic evaluation of these food products by students native to the area of recipe origin indicated the dishes to be moderately to highly acceptable. Chemical analyses of this species revealed tepary beans to be very similar in proximate composition, amino acid profile and content of various minerals to other grain legumes (cowpeas, chickpeas and fava beans) of the African/Middle Eastern region. Protein contents of tepary samples averaged 23.0%, whereas protein quality was found limiting in sulfur amino acids. Laboratory examination of raw tepary samples for antinutritional factors uncovered levels of flatulent oligo saccharides, trypsin inhibitors and phytic acid commonly associated with grain legumes. However, lectin assays revealed greater agglutination associated with tepary composites than in fava, chickpea and cowpea samples. All bean samples were simmered resulting in fully cooked materials which exhibited low levels of nutritional antagonists. Cooked beans were considered safe and nutritionally acceptable.Arizona Agricultural Experiment Station Paper No. 3814.     

日光温室番茄单叶净光合速率模型的温度修正

番茄单叶净光合速率模型是温室番茄环境调控中的核心模型之一,而温度修正模型对于正确解析番茄单叶净光合速率模型非常重要。试验根据前人确定的植物单叶净光合速率模型中最大光合速率的温度修正模型,通过对不同的CO2浓度、光强和温度条件下日光温室番茄净光合速率的测定,明确了日光温室番茄最大光合速率的温度修正模型中修正因子C的取值公式,并经拟合检验,结果表明在不同CO2浓度、不同光强条件下日光温室番茄最大光合速率下温度修正模型的模拟值与实测值拟合良好,说明可将这一温度修正模型作为日光温室番茄光合模型的温度影响子模型应用,从而使植物单叶净光合速率模型更好地适用于日光温室番茄生产。     

Plastic responses to clipping in two species of Amaranthus from the Sierra Norte de Puebla, Mexico

This study investigates the plastic responses after shoot removal of Amaranthus cruentus L. and A. hypochondriacus L. This practice is common in the Sierra Norte de Puebla, Mexico, where both species are cultivated and used as a food source during the vegetative stage. Empirical observations indicate that biomass increases in clipped plants. The experimental study carried out on both species of Amaranthus imitated local farm management. Three levels of shoot removal were applied to plants of both species: Control, 10% and 40%. In A. cruentus plants with 10% of the shoot removed produced more stalk biomass, more leaves, greater leaf area, greater length of primary branches and a larger number of secondary branches than the control plants. In A. hypochondriacus, there were no differences among levels of shoot removal in stem biomass; in general, the number of primary and secondary branches in control plants was greater than that in clipped plants. Patterns of biomass allocation revealed important differences between species, as clipped plants allocated more biomass to seeds in A. cruentus, while control plants allocated more to leaves in A. hypochondriacus. Furthermore, changes in response at the primary branch (secondary branches, leaf biomass, and area) level were observed between species. In general, clipped plants of A. cruentus overcompensate for the damage, while this response was not evident in clipped plants of A. hypochondriacus. Instead, this species showed high tolerance to damage. The phenotypically plastic responses expressed for both species can be used as a guide to improve management of these plants by local farmers from the Sierra.     

Replacement of fishmeal by soya protein concentrate in the diets of Totoaba macdonaldi (Gilbert, 1890) juveniles: effect on the growth performance,in vitro digestibility,digestive enzymes and the haematological and biochemistry parameters

The potential of soya protein concentrate (SPC) as an alternative protein source in diets for Totoaba macdonaldi juveniles was evaluated. Seven isonitrogenous and isolipidic diets were formulated containing 15–100% SPC (SPC15, SPC30, SPC45, SPC60, SPC75, SPC90 and SPC100) to replace fishmeal (FM‐protein), and a FM‐protein‐based diet without SPC was used as a reference diet (RD). Each diet was randomly assigned to triplicate groups of 20 totoaba (50 ± 1.0 g) and was fed twice daily to apparent satiation. After 60 days of experiment, effects on totoaba were evaluated. Growth performance in fish fed RD to SPC45 was similar. The maximum FM‐protein replacement for weight gain (g kg ABW^?1 day^?1) was estimated to be 34.17% using a broken‐line model. In vitro digestibility of fish fed RD, SPC15 and SPC30 was similar. Trypsin activity was higher in fish fed the RD (9.38 ± 0.52 mU × 10^?3 mg protein^?1. Chymotrypsin activity was similar in fish fed RD, SPC15 and SPC30. Activity of alkaline protease and phosphatase was similar in fish fed RD, SPC15 and SPC30. Red blood cells (RBC) were the highest in fish fed RD to SPC60. Fish fed the RD, SPC15 and SPC30 present the highest haematocrit (HT) and haemoglobin (HB) content. Diets SPC90 and SPC100 presented similar MCV and MCHC. Total protein (TP) profile overall decreased in fish fed SPC90 and SPC100, pointing to nutritional hypoproteinemia due to deficient digestion and absorption. These results indicate that SPC‐based diets could be used efficiently by totoaba with FM‐protein replacement of less than 45%.     

Nuclear genome size and chromosome analysis in <Emphasis Type="Italic">Chenopodium quinoa</Emphasis> and <Emphasis Type="Italic">C. berlandieri</Emphasis> subsp. <Emphasis Type="Italic">nuttalliae</Emphasis>

Cytogenetic characterization by karyotyping and determination of DNA content by flow cytometry of seven cultivated varieties of Chenopodium was performed. Chenopodium quinoa cultivar Barandales and C. berlandieri subsp. nuttalliae cultigens Huauzontle, Quelite and Chia roja showed 2n = 4x = 36, x = 9. Statistically insignificant genome size differences for studied varieties ranged from 2.96 pg/2C (1 Cx = 724 Mbp) in C. quinoa to 3.04 pg/2C (1 Cx = 743 Mbp) in Huauzontle. Karyotype analyses revealed the presence of nine groups of four metacentric chromosomes, including two pairs of chromosomes with satellites. The first pair of satellites was located on the largest pair of chromosomes and the second on a different pair of chromosomes in all accessions analyzed. Variation among varieties was evident in chromosome size, genome length (GL) and the position of satellites. Chia roja exhibited greatest GL (58.82 μm) and biggest chromosomes (2.04 μm). Huauzontle showed the smallest GL (45.02 μm) and shortest chromosomes (1.60 μm). Comparison of GL in studied taxa was statistically significant and allowed to define three groups according to the use given to these plants. These data indicate that they are small, very stable genomes in terms of DNA content, and they support the allotetraploid origin(s) of C. berlandieri subsp. nuttalliae and C. quinoa.     

北方日光温室长季节番茄茎节生长模拟模型

以番茄器官生长发育的生理生态过程为基础,建立了北方日光温室长季节番茄茎节生长模拟模型,它是建立番茄叶片和果实生长模拟模型的基础。供试番茄品种为“卡鲁索”和“卡特琳娜”。确定了模型中的参数如节点最大出现速率等,并对模型进行了验证试验。结果表明：番茄茎节数模拟值与实测值的变化趋势一致,平均相对误差为0.7%～9%。用散点图法验证模拟值与实测值的相关系数达0.9964,截距为-8.8,每平方米模拟值比实测值平均偏低8.8个茎节。表明模型模拟结果较好。