Effects of estrogen-depletion on rat casein gene expression

Mammary tissue from rats that had been ovariectomized and adrenalectomized 4 weeks previously was compared to that from intact rats in terms of epithelial content and hormone-responsiveness in vitro. The endocrinectomy resulted in about a 30% enlargement of the gland, but led to a loss of only about 12% of the epithelium. This estrogen-depleted epithelium was able to acquire full responsiveness in vitro to insulin in terms of the accumulation of alpha-aminoisobutyric acid, and induction of glucose-6-phosphate and gluconate-6-phosphate dehydrogenases. It was also fully responsive to cortisol in relation to the induction of NADH-cytochrome C reductase, and to prolactin in terms of total RNA synthesis. However, estrogen-depletion led to an 82% loss in the ability of a unit amount of the epithelium to synthesize casein in response to these 3 hormones, and to a similar loss in relation to the accumulation of 25K casein mRNA. Estrogen administration in vivo could prevent and reverse the casein lesion. The disparity between constitutive and casein hormone-responsiveness in the absence of estrogen is discussed in relation to cell commitment.     

The effects of artificial enrichment upon the planktonic and benthic communities in a mesotrophic to hypertrophic loch series in lowland Scotland

Phytoplankton, submerged macrophytes, zoobenthos and zooplankton communities were studied concurrently in three lochs which progressively increased in trophic state. The phytoplankton showed a change in dominance from Bacillariophyceae (Pennales) and Desmidaceae in the mesotrophic Loch of the Lowes to Bacillariophyceae (Pennales) and Cyanobacteria in eutrophic Balgavies Loch and to Bacillariophyceae (Centrales) and Chlorophyceae in hypertrophic Forfar Loch. The Nygaard Compound phytoplankton quotient rose from 1.2 in the Lowes to 12 in Forfar. There was a decrease in number of species of submerged macrophytes, and in depth of colonisation from 5 m in the Lowes to 2 m in Forfar which was proportional to the decrease in mean transparency. Macrophyte biomass, however, increased in proportion to the concentration of total phosphorus in the lochs. There was a decrease in species of littoral zoobenthos, but an increase in density of profundal benthos from the Lowes to Forfar. Zooplankton also showed an increase in density with enrichment, accompanied by changes in dominance. Calanoida were dominant in the Lowes; Cladocera in Balgavies and Cyclopoda in Forfar. The importance of these differences in understanding the effects of progressive enrichment and to the management of the lochs is discussed.     

Determining the response of African biota to climate change: using the past to model the future

Prediction of biotic responses to future climate change in tropical Africa tends to be based on two modelling approaches: bioclimatic species envelope models and dynamic vegetation models. Another complementary but underused approach is to examine biotic responses to similar climatic changes in the past as evidenced in fossil and historical records. This paper reviews these records and highlights the information that they provide in terms of understanding the local- and regional-scale responses of African vegetation to future climate change. A key point that emerges is that a move to warmer and wetter conditions in the past resulted in a large increase in biomass and a range distribution of woody plants up to 400–500 km north of its present location, the so-called greening of the Sahara. By contrast, a transition to warmer and drier conditions resulted in a reduction in woody vegetation in many regions and an increase in grass/savanna-dominated landscapes. The rapid rate of climate warming coming into the current interglacial resulted in a dramatic increase in community turnover, but there is little evidence for widespread extinctions. However, huge variation in biotic response in both space and time is apparent with, in some cases, totally different responses to the same climatic driver. This highlights the importance of local features such as soils, topography and also internal biotic factors in determining responses and resilience of the African biota to climate change, information that is difficult to obtain from modelling but is abundant in palaeoecological records.     

天山中西段不同地区雪岭云杉径向生长对气候变暖的响应差异

为研究乌苏和石河子地区雪岭云杉（Picea schrenkiana）径向生长对气候变暖的响应差异状况,利用响应函数及滑动相关分析等树轮气候学方法,研究了2个地区森林下限雪岭云杉径向生长与气候因子的响应关系。结果表明：乌苏和石河子地区雪岭云杉生长均与生长季的气候因子呈显著相关关系。但乌苏和石河子地区雪岭云杉生长对当地气候因子的响应也存在差异,乌苏地区雪岭云杉径向生长与上一年7、9月平均气温呈显著负相关,与当年8月降水、上一年9月及当年8月平均相对湿度和上一年7~10月的scPDSI呈显著正相关。石河子地区雪岭云杉径向生长与当年1月平均湿度和当年1、2月的scPDSI呈显著正相关。此外,乌苏地区树轮宽度指数具有与温度升高而下降的“分离现象”,而石河子地区树轮宽度指数具有与温度升高相一致的趋势。升温导致的水分胁迫是造成乌苏地区雪岭云杉径向生长与温度变化趋势相反的重要因素。生长季的温度和降水的增加对石河子地区雪岭云杉径向生长有促进作用。乌苏地区雪岭云杉径向生长对5~7月平均气温和降水量变化敏感性上升;石河子地区雪岭云杉径向生长对5~7月降水量变化敏感性上升,而对5~7月平均气温变化敏感性下降。结果显示,气候变化的区域差异是造成乌苏和石河子地区雪岭云杉径向生长趋势不同以及各年表序列对温度和降水变化敏感性变化的主要气候因素。     

Analysis of protein carbonylation — pitfalls and promise in commonly used methods

Abstract

Oxidation of proteins has received a lot of attention in the last decades due to the fact that they have been shown to accumulate and to be implicated in the progression and the pathophysiology of several diseases such as Alzheimer, coronary heart diseases, etc. This has also resulted in the fact that research scientists are becoming more eager to be able to measure accurately the level of oxidized protein in biological materials, and to determine the precise site of the oxidative attack on the protein, in order to get insights into the molecular mechanisms involved in the progression of diseases. Several methods for measuring protein carbonylation have been implemented in different laboratories around the world. However, to date no methods prevail as the most accurate, reliable, and robust. The present paper aims at giving an overview of the common methods used to determine protein carbonylation in biological material as well as to highlight the limitations and the potential. The ultimate goal is to give quick tips for a rapid decision making when a method has to be selected and taking into consideration the advantage and drawback of the methods.     

北戴河朱鹮野化种群非繁殖期日间活动时间分配和行为节律

于2019年7月-2020年1月对北戴河朱鹮野化种群非繁殖期的日间活动时间分配和行为节律进行了分析。结果表明,休息（41.8%）、觅食（39.7%）和理羽（13.3%）是北戴河朱鹮非繁殖期的主要行为。在行为节律上,有3个觅食高峰、2个休息高峰和2个理羽高峰。成鸟和幼鸟行为分配相似,但成鸟的警戒和社群等其他行为比例显著较高。与野生种群相比,北戴河野化种群的觅食时间显著较少,主要原因是野生个体需要花费较多时间搜寻食物,且飞行等活动的能耗较高。朱鹮在冬季的休息和理羽行为比例高于夏秋季,觅食行为则相反,这样可以在低温和大风天气降低能耗,是对北戴河气候环境的有效适应。为了提高朱鹮对多种气候环境的适应能力,为今后北戴河朱鹮的再引入奠定基础,我们建议在冬季要确保朱鹮有充足的适宜觅食地,同时在野化网笼中进行必要的环境丰容,如在网笼内增加常绿树种和阔叶树种,部分侧网上安装防风板,或在网笼中设置防风避寒的伞棚等设施,以供朱鹮进行选择。     

Role and function of cytokinin oxidase in plants

Cytokinin oxidase (CK oxidase) is widely distributed in plants and is the only enzyme that has been shown unequivocally to catalyze the catabolism of specific cytokinins (CKs) to inactive products that lack the N⁶-unsaturated side chain. Thus, the enzyme is thought to play a major role in controlling the level or species of CKs in plant tissues. However, despite its discovery more than 25 years ago, little attention has been given to the elucidation of its role and function in plant growth and development. This review seeks to bring in to context the current state of knowledge regarding the biochemical and molecular properties, regulation in undifferentiated and differentiated tissues, and recent results from studies using transgenic plants in an attempt to provide a more comprehensive understanding of the physiological significance of the enzyme in plants. Notwithstanding species, tissue and other specific differences, in general, CK oxidase appears to contribute to CK homeostasis in plants. However, complete clarity as to its function awaits purification of the protein to homogeneity and the ultimate development of requisite molecular probes.     

潍坊市2007-2012年水痘流行病学分析

目的：了解潍坊市2007-2012年水痘的流行病学特征,为控制水痘策略提供科学依据。方法对2007-2012年疾病监测信息报告系统上报的水痘病例资料进行描述流行病学分析。结果2007-2012年潍坊市共报告水痘病例2256例,年均发病率为4．22/10万,11月至次年1月及4-6月为发病高峰期;发病主要集中于4～9岁和10～24岁者,其发病率分别为28．76/10万和6．85/10万。发病者主要是学生、散居儿童和托幼儿童,分别占总病例数的52．13％、19．99％、16．93％。报告暴发疫情12起,主要发生在学校和托幼机构。结论潍坊市发生的水痘以4～9岁和10～24岁者为高发人群,应加强对适龄儿童水痘疫苗的查漏补种工作,加强学校及托幼机构传染病管理,减少发生暴发疫情。     

Evaluating spatial within plot crop variability for different management practices with an optical sensor?

Subsoil constraints to root growth exacerbate frequent water and nutrient limitations to crop yields in Mediterranean-type environments. Amelioration of subsoil constraints can relieve these limitations by opening root-access to subsoil water and nutrients. However, decisions in subsoil amelioration are hampered by seasonally variable yield responses in these environments. We used the APSIM model to analyse the impact of subsoil constraints on yield and yield variability. The simulated yield data were used to calculate the financial benefits of subsoil amelioration across several scenarios. There was a strong yield-dependence on accessible soil water governed by root depth. Root depth development was limited to a minimum of either the effect of subsoil constraints or the weather-dependent depth of the soil wetting front. Insufficient rainfall in dry years or in a drier region often resulted in shallow soil wetting fronts and correspondingly shallow roots even in the absence of subsoil compaction. In these situations, there is little response to subsoil amelioration. Positive yield responses and positive financial returns to subsoil amelioration are therefore greater in good rainfall years and are more likely in a wetter region. A yield response to amelioration is also greater in coarser textured sand than finer textured sandy loam in an average rainfall season because the same amount of rainfall results in a deeper wetting front in sand than in sandy loam. Hence, roots in a sand are required to grow deeper compared to a sandy loam to access the same amount of water and therefore benefited more from subsoil amelioration in an average rainfall year. In wet years, sands leach more nitrate than sandy loam, which decreases yields and the response to subsoil amelioration in sands is more than in the sandy loam. Environmental threats occur along with yield loss when roots cannot access subsoil water. These include increased nitrate leaching and deep drainage due to unused water remaining in the soil profile. By allowing roots to access deep soil water, ameliorating subsoil is expected to yield financial gains in average to good rainfall seasons and decrease the environmental risk of drainage and leaching loss. The financial gains are expected to offset potential financial losses in dry and dry finish seasons especially in coarser textured soils and wetter environment. Responsible Editor: Jan Vos.     

Zinc response in pigeon pea as influenced by genotypic variability

Seven improved cultivars of pigeon pea (Cajanus cajan (L.) Mill sp.) were evaluated at 0 (original Zn deficient soil), 5 and 50 ppm Zn levels under greenhouse conditions. Plants were harvested at 6 weeks after sowing and at maturity. Responses to 5 ppm Zn in shoot at 6 weeks of growth, and in leaf, stem, pod-hull and grain at maturity ranged from 63 to 387, 37 to 116, 15 to 73,9 to 145 and 51 to 200%, respectively. Application of 50 ppm Zn in most of the cultivars did not markedly affect the yield of different plant parts. Zinc concentration at 0 Zn level in shoot at 6 weeks of growth and in leaf, stem, pod-hull and grain of different genotypes varied from 9.8 to 14.5, 13.7 to 21.2, 10.8 to 16.7, 4.17 to 5.83 and 9.2 to 16.7 ppm, respectively, and the increase in concentration with 5 ppm applied Zn ranged from 28 to 248, 28 to 89, 27 to 85, 20 to 142, and 105 to 254 per cent, respectively. The concentration further increased with an increase in Zn level to 50 ppm. There was less variation in the yield and tissue Zn concentration of different genotypes after Zn application. Phosphorus concentration at 0 Zn level in shoot at 6 weeks of growth, and in leaf, stem, pod-hull and grain of different genotypes varied from 0.50 to 0.71, 0.18 to 0.31, 0.11 to 0.24, 0.15 to 0.20 and 0.43 to 0.58% respectively. Zinc decreased P in all plant parts but relative decrease was more in vegetative parts than in grain. The variability in Zn response among pigeon pea genotypes could partly be attributed to the maintenance of proper P/Zn balance in metabolically active plant parts, such as, leaf, and partly to their capacity to exploit soil Zn and to translocate it to the above-ground parts.Contribution from the Department of Soils, Haryana Agricultural University, Hissar (India).     

Reproduction of Pelagia noctiluca in the central and northern Adriatic Sea

The sequence of vitellogenesis as related to size increase of the oocytes of Pelagia noctiluca (Forskål) (Scyphozoa, Semaeostomeae) was examined to assess the influence of climatic factors on its reproductive period in the central and northern Adriatic Sea. From 1981 to 1985, 5 specimens with similar diameter were sampled each month. One ovary was excised from each individual and examined both with a videoanalyzer, to count the oocytes and to check their size distribution, and through histology to assess the stage of maturation in relation to the diameter. Oocytes of all stages were present in the ovaries of individuals down to a bell diameter of 3.5 cm. Thus reproduction occurs throughout the year in the central and north Adriatic Sea. However, the number of oocytes in different developmental stages in a gonad may range from a minimum value recorded in summer to two peaks in spring and autumn. The quantitative distribution is related to sea temperature and thus to metabolic rate, and to food availability.     

Differences in Subadult Behaviors of Chimpanzees Living in Peer Groups and in a Family Group

In several primate species, peer-group rearing conditions affect the development of social behavior. We compared the social behavior of adolescent chimpanzees reared in peer groups and in a family group to see whether chimpanzees raised under different regimes show differences in sexual behavior, teasing behavior, and grooming behavior and in their ability to cope with support strategies. Surprisingly, the lack of opportunity to practice or to watch in peer groups had no measurable effect on the development of normal sexual behavior in adolescence and adulthood. Peer-group individuals groomed each other as much as peers did in the zoo. Sex differentiation in reaction to teasing and in conflict initiatives may indicate only an earlier sex differentiation in the zoo than in the peer group. This result may be attributed to the difference in demographic composition of the groups instead of some inherent difference in skill. Peer-group chimpanzees simply cannot find adult partners with which they may preferably test their position. However, there was a lack of sex differentiation in the reaction to teasing and in the number of conflicts started; both are indications of lesser sex-role development in the peer-group adolescents. Furthermore, the frequency of giving support to peers in conflicts differed, which suggests a greater ability in zoo adolescents to cope with support strategies. Accordingly, providing more natural conditions than is usual in laboratories may still add considerably to chimpanzee well-being.     

The role of protein translocation in the regulation of glycogen metabolism

Early biochemical analyses of metabolic pathways assumed that the free diffusion of substrates and enzymes in an evenly mixed cellular space provided the interactions that enabled reactions to proceed. Metabolic complexes have since been shown to assemble and disassemble in response to changes in cellular conditions, and in turn, to channel metabolic intermediates within discreet cellular compartments, allowing for the efficient use or storage of energy. A fundamental component to the formation of metabolic complexes and the channeling of metabolites is the translocation of enzymes in response to specific extra- and intracellular signals. These generalities play an important role in the metabolism of glucose to glycogen within skeletal muscle and liver. In this review, the similarities and differences in skeletal muscle and liver glucose metabolism with regards to glucose transport and intracellular processing will be addressed during the fasted to fed transition. More specifically, the importance of isoform expression and protein translocation in the tissue specific control of glucose homeostasis will be covered.     

Alien and native plant seed dispersal by vehicles

Vehicles play a significant role in spreading plants, both in terms of quantity and quality (species). This study was conducted in Southeast Queensland to determine the role of utility vehicles in spreading seeds. These vehicles were found to carry up to 397 seeds per vehicle and in all four seasons of the year, with the majority of these species being alien to Australia and/or Queensland. The largest seed loads were found in autumn in this summer rainfall environment. Seeds were shown to attach to all parts of the vehicle, often in mud picked up from the ground, affixed directly to the engine or radiator, or carried into the cabin by the driver. Therefore, much of the seed load is to be found on the underside, on the back and front mudguards while smaller collections were found in the cabin, on the radiator and engine, and on the tyres. Fewer viable seeds were found on the engine, presumably as desiccation and heat contributed more to their death on this part of the vehicle. One method used to reduce weed seed spread by vehicles in Queensland is washing and vacuuming of vehicles. From the present study, these procedures would need to be applied to all parts of the vehicle and in all seasons of the year.     

Polyamines and plant disease

The diamine putrescine and the polyamines spermidine and spermine are found in a wide range of organisms from bacteria to plants and animals. They are basic, small molecules implicated in the promotion of plant growth and development by activating the synthesis of nucleic acids. Polyamine metabolism has long been known to be altered in plants responding to abiotic environmental stress and to undergo profound changes in plants interacting with fungal and viral pathogens. Polyamines conjugated to phenolic compounds, hydroxycinnamic acid amides (HCAAs), have been shown to accumulate in incompatible interactions between plants and a variety of pathogens, while changes in the diamine catabolic enzyme diamine oxidase suggest a role for this enzyme in the production of hydrogen peroxide during plant defence responses. More recent work has suggested a role for the free polyamine spermine in the hypersensitive response of barley to powdery mildew and particularly in tobacco to TMV. The prospects for the genetic manipulation of HCAA levels in plants as a means of both defining their role in plant defence and in the generation of disease resistant plants is discussed briefly.     

Altered behavioural adaptation in mice with neural corticotrophin-releasing factor overexpression

Overproduction of corticotrophin-releasing factor (CRF), the major mediator of the stress response, has been linked to anxiety, depression and addiction. CRF excess results in increased arousal, anxiety and altered cognition in rodents. The ability to adapt to a potentially threatening stimulus is crucial for survival, and impaired adaptation may underlie stress-related psychiatric disorders. Therefore, we examined the effects of chronic transgenic neural CRF overproduction on behavioural adaptation to repeated exposure to a non-home cage environment. We report that CRF transgenic mice show impaired adaptation in locomotor response to the novel open field. In contrast to wild-type (WT) mice, anxiety-related behaviour of CRF transgenic mice does not change during repeated exposure to the same environment over the period of 7 days or at retest 1 week later. We found that locomotor response to novelty correlates significantly with total locomotor activity and activity in the centre at the last day of testing and at retest in WT but not in CRF transgenic mice. Mice were divided into low responders and high responders on the basis of their initial locomotor response to novelty. We found that differences in habituation and re-exposure response are related to individual differences in locomotor response to novelty. In summary, these results show that CRF transgenic mice are fundamentally different from WT in their ability to adapt to an environmental stressor. This may be related to individual differences in stress reactivity. These findings have implications for our understanding of the role of CRF overproduction in behavioural maladaptation and stress-related psychiatric disorders.     

The significance of ectomycorrhizal fungi for sulfur nutrition of trees

Sulfur nutrition of plants is largely determined by sulfate uptake of the roots, the allocation of sulfate to the sites of sulfate reduction and assimilation, the reduction of sulfate to sulfide and its assimilation into reduced sulfur-containing amino acids and peptides, and the allocation of reduced sulfur to growing tissues that are unable to fulfill their own demand for reduced sulfur in growth and development. Association of the roots of pedunculate oak (Quercus robur L.) and beech (Fagus sylvatica L.) trees with ectomycorrhizal fungi seems to interact with these processes of sulfur nutrition in different ways, but the result of these interactions is dependent on both the plant and the fungal partners. Mycorrhizal colonisation of the roots can alter the response of sulfate uptake to sulfate availability in the soil and enhances xylem loading and, hence, xylem transport of sulfate to the leaves. As a consequence, sulfate reduction in the leaves may increase. Simultaneously, sulfate reduction in the roots seems to be stimulated by ectomycorrhizal association. Increased sulfate reduction in the leaves of mycorrhizal trees can result in enhanced phloem transport of reduced sulfur from the leaves to the roots. Different from herbaceous plants, enhanced phloem allocation of reduced sulfur does not negatively affect sulfate uptake by the roots of trees. These interactions between mycorrhizal association and the processes involved in sulfur nutrition are required to provide sufficient amounts of reduced sulfur for increased protein synthesis that is used for the enhanced growth of trees frequently observed in response to ectomycorrhizal association. This revised version was published online in June 2006 with corrections to the Cover Date.     

Hydrogen bonding markedly reduces the pK of buried carboxyl groups in proteins

The ionizable groups in proteins with the lowest pKs are the carboxyl groups of aspartic acid side-chains. One of the lowest, pK=0.6, is observed for Asp76 in ribonuclease T1. This low pK appeared to result from hydrogen bonds to a water molecule and to the side-chains of Asn9, Tyr11, and Thr91. The results here confirm this by showing that the pK of Asp76 increases to 1.7 in N9A, to 4.0 in Y11F, to 4.2 in T91V, to 4.4 in N9A+Y11F, to 4.9 in N9A+T91V, to 5.9 in Y11F+T91V, and to 6.4 in the triple mutant: N9A+Y11F+T91V. In ribonuclease Sa, the lowest pK=2.4 for Asp33. This pK increases to 3.9 in T56A, which removes the hydrogen bond to Asp33, and to 4.4 in T56V, which removes the hydrogen bond and replaces the -OH group with a -CH(3) group. It is clear that hydrogen bonds are able to markedly lower the pK values of carboxyl groups in proteins. These same hydrogen bonds make large contributions to the conformational stability of the proteins. At pH 7, the stability of D76A ribonuclease T1 is 3.8 kcal mol(-1) less than wild-type, and the stability of D33A ribonuclease Sa is 4.1 kcal mol(-1) less than wild-type. There is a good correlation between the changes in the pK values and the changes in stability. The results suggest that the pK values for these buried carboxyl groups would be greater than 8 in the absence of hydrogen bonds, and that the hydrogen bonds and other interactions of the carboxyl groups contribute over 8 kcal mol(-1) to the stability.     

Does the response to cocaine differ as a function of sex or hormonal status in human and non-human primates?

Stimulant abuse continues to be a growing problem among women. Over the last 10-15 years, an increasing number of studies have focused on factors that may be implicated in stimulant abuse in women as compared to men, including the role of hormonal fluctuations across the menstrual cycle. Numerous preclinical studies have documented that female rodents are more sensitive than male rodents to the behavioral effects of stimulant administration and the hormone estradiol is involved in the enhanced response to stimulants observed in females. In contrast, fewer studies have been conducted in humans and non-human primates addressing the role of sex and gonadal hormones on the effects of cocaine. This review paper presents a recent update on data collected in our Human Cocaine Challenge Laboratory and our Non-human Primate Laboratory, including analysis of cocaine pharmacokinetics, sex differences, the menstrual cycle, and the role of progesterone in modulating the response to cocaine. Our studies indicate that there is minimal evidence that the response to intranasal cocaine varies across the menstrual cycle or between men and women. In contrast, the response to smoked cocaine is greater in the follicular phase than the luteal phase and differences between men and women generally only emerge when men are compared to women in the luteal phase. In terms of potential hormonal mechanisms for these differences, the hormone progesterone attenuates the subjective response to cocaine. With respect to cocaine self-administration, there are minimal changes across the menstrual cycle in both humans and non-human primates. Thus, there is converging evidence across a range of species that the behavioral effects of cocaine (1) differ between males and females, (2) differ in relation to hormonal fluctuations, (3) can be attenuated by progesterone (at least in females), and (4) do not appear to be related to differences in cocaine pharmacokinetics.