Patterns of communities in the tropics

Tropical countries have many times more species of most taxa than temperate ones, and small areas in the tropics have a smaller multiple of the number of species of small temperate areas. Where many species are present, abundances tend to be more equal and geographic distributions more spotty. Most tropical environments are less seasonal and more productive, and the dry areas and mountains which are relatively more seasonal and less productive have fewer species. The species which have reached offshore islands are often much commoner there and occupy expanded habitats.
To account for these relations, the following general hypothesis seems necessary:species interactions are important and the tropics have a head start on speciation. The head start, or greater rate, allows extra species to pile up in the tropics, but because of the importance of competition, no single area becomes as greatly enriched. Rather, faunal differences between areas increase. The lesser excess of tropical species in small areas is largely due to greater productivity and reduced seasonality which make marginal ways of life profitable. With more overlap in resources, the closely packed tropical species have more uniform abundances and the coexistence of these species is more precarious, causing the spotty geographic distributions.
Neither the species diversity of the food supply nor the longer breeding season (supposedly allowing staggered nesting seasons with an early shift and a later shift) is relevant to bird species diversity.     

Beautiful parents have more daughters: a further implication of the generalized Trivers-Willard hypothesis (gTWH)

The generalized Trivers-Willard hypothesis (gTWH) [Kanazawa, S., 2005. Big and tall parents have more sons: further generalizations of the Trivers-Willard hypothesis. J. Theor. Biol. 235, 583-590) proposes that parents who possess any heritable trait which increases the male reproductive success at a greater rate than female reproductive success in a given environment will have a higher-than-expected offspring sex ratio, and parents who possess any heritable trait which increases the female reproductive success at a greater rate than male reproductive success in a given environment will have a lower-than-expected offspring sex ratio. One heritable trait which increases the reproductive success of daughters much more than that of sons is physical attractiveness. I therefore predict that physically attractive parents have a lower-than-expected offspring sex ratio (more daughters). Further, if beautiful parents have more daughters and physical attractiveness is heritable, then, over evolutionary history, women should gradually become more attractive than men. The analysis of the National Longitudinal Study of Adolescent Health (Add Health) confirm both of these hypotheses. Very attractive individuals are 26% less likely to have a son, and women are significantly more physically attractive than men in the representative American sample.     

DIVERSITY AND NICHE EVOLUTION ALONG ARIDITY GRADIENTS IN NORTH AMERICAN LIZARDS (PHRYNOSOMATIDAE)

Deserts occupy approximately 12% of the Earth's land surface, and are thought to have species poor but highly specialized biotas. However, few studies have examined the evolutionary origins of desert biotas and of diversity patterns along aridity gradients. Further, it is unclear if species occurring in more extreme conditions on a given niche axis (i.e., precipitation) are more specialized for those conditions (i.e., have narrower niche breadths). We address these questions here using a time‐calibrated phylogeny and climatic data for 117 species of phrynosomatid lizards. Phrynosomatids are the most species‐rich family of lizards in North America, and are found from deserts to rainforests. Surprisingly, we find that phrynosomatids have higher richness in more arid environments. This pattern occurs seemingly because they have been present in more arid habitats longer (～55 million years), and lineages in mesic environments are recently derived from more arid‐dwelling ancestors. We find little support for the hypothesis that species in more extreme environments are more specialized. Instead, many desert‐dwelling species are broadly distributed, and species in the most mesic environments have the broadest niche breadths. In summary, phrynosomatids offer a counterexample to the idea that arid regions are inhabited by a small number of recent and highly specialized lineages.     

国内外湿地生态系统研究进展

湿地生态系统具有重要的生态功能和社会经济价值。由于诸多因素的影响,目前全球范围内相当一部分湿地生态系统已经丧失或正在遭受不同程度的威胁,湿地生态系统已经成为近年来相关领域研究的热点之一。近年来,国内外湿地生态系统的研究主要集中在湿地生态系统生物多样性本底资料的调查、湿地生态系统的动态以及湿地生态系统胁迫因子研究、退化湿地生态系统的重建和管理,以及恢复湿地有效性的评估体系等4个方面。一些新方法、新技术也不断应用于湿地生态系统研究中。除了自然湿地外,人工湿地的构建和评价体系的建立也成为该领域研究的热点方向。影响湿地生态系统的因素涉及到自然、社会经济、文化等多个方面,加之湿地类型多样性,因此开展更为广泛的湿地生态系统结构、功能和动态的研究是十分必要的。同时,对特定区域内的湿地生态系统修复过程中的关键技术(包括物种的选择等)的研究、新方法和新手段的应用研究也应该在湿地生态系统研究中给予特别关注。     

A comparison of structural and contextual features of middle school children's playful and aggressive fighting

This study compared structural and contextual features of playful [rough-and tumble play (r/t)] and aggressive fighting based on direct playground observations of two classes of 8 and two classes of 11 year old children. Most bouts of r/t and aggressive fighting were dyadic, but significantly more bouts of the former involved three or more participants than the latter. Rough-and-tumble play was found to contain more individual action patterns than aggressive fighting, but the latter was more varied in form than some earlier studies had shown. Both wrestling and chasing were seen more in r/t than aggressive fighting, but restraint in bouts of chasing was not more common in playful chasing than aggressive chasing. Positive and neutral facial expressions were more characteristic of r/t, and negative facial expressions were more characteristic of aggressive fighting. Rough-and-tumble initiations were more likely to receive an r/t response and less likely to receive an aggressive response than were aggressive initiations. Participants in r/t were more likely to have been together than to have been apart prior to the encounter, but this tendency was strongly mediated by sex. In three out of the four classes, children were more likely to have been together prior to same sex r/t interactions and to have been apart prior to mixed sex r/t interactions. Participants in r/t were not significantly more likely to have been together beforehand than participants in aggressive fighting. Finally, while most bouts of r/t led to the participants remaining together, the proportion that did so was not significantly greater than was the case for bouts of aggressive fighting. Possible reasons why r/t and aggressive fighting did or did not differ in these ways are discussed.     

植物高效吸收和利用磷营养的遗传学研究进展

近些年来,人们对植物营养性状的遗传学背景日益了解,特别是磷素营养。随着分子生物学的快速发展,磷素营养的研究已深入到分子水平并且取得了可喜的成绩。本文从植物体内调控磷吸收利用的相关QTLs定位,缺磷诱导的基因表达,植物体内的磷调控系统,磷转运子及与磷有关的突变体的研究作一概括。     

植物高效吸收和利用磷营养的遗传学研究进展

近些年来 ,人们对植物营养性状的遗传学背景日益了解 ,特别是磷素营养。随着分子生物学的快速发展 ,磷素营养的研究已深入到分子水平并且取得了可喜的成绩。本文从植物体内调控磷吸收利用的相关QTLs定位 ,缺磷诱导的基因表达 ,植物体内的磷调控系统 ,磷转运子及与磷有关的突变体的研究作一概括。     

Declining Odds: Kinship, Women's Employment, and Political Economy in Rural Mexico

Some women in San Cosme Mazatecochco, a rural community in central Mexico, whose families have more diverse networks and a slight economic advantage, use the community's flexible kinship system to get more secure employment. But their ability to do so is limited by the larger political economy. As the Mexican economy deteriorates for working-class Mexicans and the class system becomes more closed, more women participate in the labor force and more women have marginal employment, [political economy, kinship, women, class, Mexico]     

Factors affecting nutritional status in female adults in Dhaka slums, Bangladesh

This study looks at women from the slums in Mohammadpur, Dhaka, Bangladesh, where 54 percent of women's BMI was less than 18.5. Fifty percent of the Dhaka slum population lived below the poverty line. Logistic regression showed that women with income above 1,500 taka per capita were 1.78 times more likely to have a higher BMI (odds ratio 1.7863; CI = 0.671-3.639). Women with their own savings were 1.89 times more likely to have higher BMI (odds ratio 1.879; CI = 0.01163-1.6431). Women were 4.5 times more likely to have a higher BMI when food expenditure per capita above 559 taka per month (odds ratio 4.55; CI = 1.0302-8.0799). Women were 1.82 times more likely to have higher BMI when there was a break even situation in financial status (odds ratio 1.8212; CI = -015709-3.6285). Female headed households were 3.3 times more likely to have a higher BMI compared to women living in male headed households (odds ratio 3.2966; CI = 0.33711-6.25620). Women who work 15-23 days per month were 2.3 times more likely to have a higher BMI (odds ratio 2.33; CI = 0.1133-4.5600). Women who are the budget manager are 1.12 times more likely to have a higher BMI (odds ratio 1.125; CI = 0.29296-2.0966). Where as a husband who beats his wife is 1.83 more likely to have a poorer BMI (odds ratio 1.8312; CI = -3.72596-0.17508). Women who have no marriage documents and women who take days off due to illness less than 11 days per month were more likely to have a poorer BMI (odds ratio 0.5567; CI = -0.049339-2.8379; odds ratio 0.7569; CI = 0.183167-2.0002). Women's nutritional status and well being can influence their ability to provide for themselves and their families and the demonstration of a relationship between measures of women's autonomy and control in the household and women's nutritional status is an important indication of the importance of these sociological constructs. Women's participation in work outside the home may be a factor increasing their autonomy. The identification of relationships between women's autonomy and control and their physical well being should provide further leverage for policy change that will enable women to escape some traditional roles and to contribute as more equal partners with men in the future of Bangladeshi society.     

Glycerophospholipid metabolism in neuronal and glial cell-enriched fractions

The metabolism of phospholipids in separated glial and neuronal cells has been reviewed in this paper. Lipids are more abundant in glia; on the other hand, in vivo experiments performed with labeled precursors have indicated that lipid turnover is faster in neurons (with the possible exception of oligodendroglia). Biosynthetic and catabolic enzymes of lipid metabolism have been studied in separated cells (mainly in neurons and astroglia) and have been shown to be almost always more active in neurons. Also base exchange is probably more active in these cells. Therefore the results of in vitro and in vivo experiments indicate that neurons are more active than astroglia in metabolizing glycerophospholipids.     

Violent men have more sons: further evidence for the generalized Trivers-Willard hypothesis (gTWH)

The generalized Trivers-Willard hypothesis (gTWH) [Kanazawa, S., 2005a. Big and tall parents have more sons; further generalizations of the Trivers-Willard hypothesis. J. Theor. Biol. 235, 583-590] proposes that parents who possess any heritable trait which increases the male reproductive success at a greater rate than female reproductive success in a given environment have a higher-than-expected offspring sex ratio, and parents who possess any heritable trait which increases the female reproductive success at a greater rate than male reproductive success in a given environment have a lower-than-expected offspring sex ratio. One heritable trait which increases the reproductive success of sons significantly more than that of daughters in the ancestral environment is the tendency toward violence and aggression. I therefore predict that violent parents have a higher-than-expected offspring sex ratio (more sons). The analysis of both American samples and a British sample demonstrates that battered women, who are mated to violent men, have significantly more sons than daughters.     

Protein disorder prediction by condensed PSSM considering propensity for order or disorder

Background  

More and more disordered regions have been discovered in protein sequences, and many of them are found to be functionally significant. Previous studies reveal that disordered regions of a protein can be predicted by its primary structure, the amino acid sequence. One observation that has been widely accepted is that ordered regions usually have compositional bias toward hydrophobic amino acids, and disordered regions are toward charged amino acids. Recent studies further show that employing evolutionary information such as position specific scoring matrices (PSSMs) improves the prediction accuracy of protein disorder. As more and more machine learning techniques have been introduced to protein disorder detection, extracting more useful features with biological insights attracts more attention.     

Relationship of prenatal alcohol use with maternal and prenatal factors in American Indian women

Demographic factors and patterns of substance use among women who did not consume alcohol during pregnancy were compared to women who did consume alcohol during pregnancy. One-hundred seventy-seven Northern Plains Indian women who received prenatal care at an urban clinic in a rural state were screened for substance use as part of the validation study with a self-administered questionnaire. Women who drank during pregnancy were more likely to be single and have less education than women who did not drink. While most of the women in the study had available transportation resources, the women who drank during pregnancy were less likely to have transportation than the women who did not drink. Women who drank during pregnancy consumed more alcohol more frequently before pregnancy than did women who drank before but not during pregnancy. Compared to women who did not drink during pregnancy, women who drank during pregnancy were more likely to smoke cigarettes and use illicit drugs, to have parents who drank, to feel they drank the same or more than other pregnant women, or to have experienced more relationship breakups and physical and emotional abuse. Prenatal patients who drink alcohol during pregnancy need more intensive counseling regarding their multiple risk behaviors.     

More compact protein globules exhibit slower folding rates

We have demonstrated that, among proteins of the same size, alpha/beta proteins have on the average a greater number of contacts per residue due to their more compact (more "spherical") structure, rather than due to tighter packing. We have examined the relationship between the average number of contacts per residue and folding rates in globular proteins according to general protein structural class (all-alpha, all-beta, alpha/beta, alpha+beta). Our analysis demonstrates that alpha/beta proteins have both the greatest number of contacts and the slowest folding rates in comparison to proteins from the other structural classes. Because alpha/beta proteins are also known to be the oldest proteins, it can be suggested that proteins have evolved to pack more quickly and into looser structures.     

靛蓝及其同类色素的微生物生产与转化

靛蓝类色素广泛应用于印染、食品和医药工业, 其环境友好的合成或生产途径越来越受到人们的关注, 特别是微生物生物合成。已经鉴定和分离了能够合成靛蓝类色素的多种微生物, 并且明确了起催化作用的主要是单加氧酶和双加氧酶。已经克隆和利用了一些加氧酶的基因, 构建了工程菌, 优化了其发酵过程。同时, 微生物合成靛蓝的生物转化也已经起步。这些进展将带来环境友好的靛蓝类色素的合成与生产。     

Enthesis bilateral asymmetry in humans and African apes

Entheses (skeletal muscle and tendon attachment sites) have often been used to infer handedness and activity variability among human populations. However, the specific roles that intensity vs. frequency of muscle contractions play in modifying entheses are not well understood and the assumption that entheses reflect muscle activity levels has been challenged. This study explores the effect of habitual muscular activity on enthesis morphology in humans and African apes by investigating bilateral asymmetry in the forelimbs and hindlimbs of these taxa. Humans have generally more developed entheses in the lower limb while African apes have generally more developed entheses in the forelimbs. All species studied have more asymmetric forelimbs than hindlimbs except humans that show more asymmetrical expression of bony spurs in the lower limbs than in the upper limbs. When comparing species, humans are always more asymmetric in ethesis development than apes for both the forelimbs and hindlimbs, which reflects the relatively greater asymmetry in limb use in humans and the more symmetric use in apes. Enthesis development may reflect cross-symmetry patterns in humans and, more subtly, a moderate handedness in apes during manipulative activities. This study suggests that enthesis morphology provides information on muscle activity levels, with greater development of entheses associated with more habitual or powerful muscle use. The general similarity of ape and human responses to muscle activity suggests that muscle activity influenced enthesis development in Plio-Pleistocene hominins and that interpretation of muscle markings in these fossils can provide data for functional inferences in these extinct species.     

Comparison of locomotor behaviour between white-headed langurs Trachypithecus leucocephalus and Francois' langurs T.fran(c)oisi in Fusui, China

We studied the locomotor behaviour of white-headed langurs Trachypithecus leucocephalus and Fran(c)ois' langurs T.fran(c)oisi to test two hypotheses: (1) these monkeys have evolved locomotor ability to support their activities on limestone hills,and (2) Fran(c)ois' langurs have evolved more diverse locomotor skills than white-headed langurs. Data were collected from 1996 - 1998 and in 2005 in Fusui Nature Reserve,Guangxi,and showed that the two species had similar locomotor types,but Francois' langurs had more locomotor modes (26) than white-headed langurs (12). Quadrupedal walking and leaping were two major types,and white-headed langurs were more arboreal than Fran(c)ois' langurs. We suggest that,while keeping their ancestral locomotor types,the two species have evolved new types allowing them to live on limestone cliffs. Compared to white-headed langurs,Francois' langurs have more diverse locomotor modes that probably have allowed them to live in more habitat types. As an evolutionary outcome,Fran(c)ois' langurs have a larger distribution range.     

Specific features of the clinical course and angiographic pattern in chronic coronary artery occlusion

Particular features of coronary angiography and clinical presentation of coronary artery disease have been studied in patients with chronic total coronary occlusion. Chronic total coronary occlusion is defined as TIMI 0 or TIMI I type flow in the artery for more than three days. Patients with coronary occlusion have more severe course of coronary artery disease: they more often suffer myocardial infarction and high gradations of angina. Myocardial function is much more affected if there is occlusion of left descending artery, or there are no signs of intercoronary collaterals.     

Frugivorous and animalivorous bats (Microchiroptera): dental and cranial adaptations

The most derived fruit-eating bats have small canines, wide palates and molars with a distinctive labial rim. Paracone and metacone have moved from a dilambdodont position in the middle of the tooth to the labial side of the tooth where they form the labial cutting edge. Along with the well-developed and close fitting labial cutting edges of the premolars and canines, this cutting edge skirts nearly the entire perimeter of the palate. The labial rim of the lower teeth fit inside the labial rim of the upper teeth like two cookie cutters nesting one inside the other. Frugivores have a greater allocation of tooth area at the anterior end of the toothrow, while animalivorous species have more at the posterior end of the toothrow. The area occupied by canines of predators of struggling prey is greater than that for bats that eat non-struggling prey like fruit. In addition, frugivores have wider palates than long while many carnivores have longer palates than wide. Omnivores appear to have a more equal allocation of space to more kinds of teeth, particularly the incisors and non-molariform premolars, on the toothrow than do frugivores or animalivores. The mechanical nature of different food items is discussed and the suggestion made that describing foods in terms of their texture may be more important in tooth design than whether they are fruit or insect or vertebrate.     

Influence of growth rate on protein synthesis and distribution of ribosomes in HeLa cells.

HeLa cells have been grown at different rates in steady-state continuous and semi-continuous culture. Slowly growing cells contain more protein and less RNA than rapidly growing cells, but appear to synthesize protein by less efficient use of the available RNA. The rate of RNA accumulation increases rapidly with increasing growth rate and rapidly growing cells contain more ribosomal subunits, and more and larger polysomes, but have fewer monoribosomes than slowly growing cells.