Trisomy represses Apc(Min)-mediated tumours in mouse models of Down's syndrome

Epidemiological studies spanning more than 50 yr reach conflicting conclusions as to whether there is a lower incidence of solid tumours in people with trisomy 21 (Down's syndrome). We used mouse models of Down's syndrome and of cancer in a biological approach to investigate the relationship between trisomy and the incidence of intestinal tumours. Apc(Min)-mediated tumour number was determined in aneuploid mouse models Ts65Dn, Ts1Rhr and Ms1Rhr. Trisomy for orthologues of about half of the genes on chromosome 21 (Hsa21) in Ts65Dn mice or just 33 of these genes in Ts1Rhr mice resulted in a significant reduction in the number of intestinal tumours. In Ms1Rhr, segmental monosomy for the same 33 genes that are triplicated in Ts1Rhr resulted in an increased number of tumours. Further studies demonstrated that the Ets2 gene contributed most of the dosage-sensitive effect on intestinal tumour number. The action of Ets2 as a repressor when it is overexpressed differs from tumour suppression, which requires normal gene function to prevent cellular transformation. Upregulation of Ets2 and, potentially, other genes involved in this kind of protective effect may provide a prophylactic effect in all individuals, regardless of ploidy.     

微波裂解温度对菌糠生物炭特性的影响

为了探讨菌糠微波裂解产生的生物质炭作为土壤改良剂的可行性,试验分析不同裂解温度下生物质炭的理化特性,以期探究菌糠生物质炭的理化特征,以及微波裂解温度对它的影响变化规律.结果表明,微波裂解温度对菌糠裂解产物生物质炭的性质具有显著影响,较低裂解生物炭元素组成含量较高,但裂解不完全;而随着裂解温度升高,生物质炭表现出较高的pH值10.43、持水量7.886 m L·g~(-1)和比表面积189.38 m~2·g~(-1).研究对于菌糠生物质炭在土壤改良、固碳减排等方面的应用具有一定的借鉴意义.     

First described fossil representatives of the parasitoid wasp taxa Asaphesinae n. n. and Eunotinae (Hymenoptera: Chalcidoidea: Pteromalidae sensu lato) from Eocene Baltic amber

ABSTRACT

New Baltic amber species of Pteromalidae sensu lato are described, from two different subfamilies, Asaphesinae n. n. and Eunotinae. Asaphesinae is provided as a replacement name for Asaphinae Ashmead 1904, which is a junior homonym of the trilobite family Asaphidae Burmeister 1843. Coriotela lasallei gen. n., sp. n.. and Butiokeras costae gen. n., sp. n.. are described as the first known fossil species of Asaphesinae and Eunotinae, respectively. These species establish the minimum known age of both groups in the Eocene. Taxonomic changes are also proposed for some extant species. The genus Desantisiana Neder de Román syn. n.. is found to be a junior synonym of Notoglyptus, and its only described species is transferred as Notoglyptus jujuyensis (Neder de Román) comb. n.. The tribe Calyconotiscini, previously classified in Eunotinae, is abolished and Calyconotiscus Narendran & Saleem is transferred to Pireninae.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:7A107FF9-28E7-40AA-8A9B-71321E476C07     

NUMERICAL EVALUATION OF THE PRINTABILITY OF PAPER SURFACES

This paper describes a technique that numerically defines the print quality potential of a sheet of paper through density measurements BEFORE it is shipped, by measurement of the micro-density of the sheet.The technique can be used to quantify the differences between two sides of a sheet of paper, between batches produced at different times on the same machine or to compare the same grade from different sources.     

Sur le rôle possible des deux acides nucléiques dans la cellule vivante

Summary According to the writer's theory a great number of different desoxyribonucleic and ribonucleic acids exist in each cell: desoxyribonucleic acids in the nucleus (genes) and ribonucleic acids in the cytoplasm (microsomes). Through catalytic actions the macromolecular desoxyribonucleic acids govern the building of macromolecular ribonucleic acids, and, in turn, these control the production of cytoplasmic enzymes. In truth, the enzymic equipment results simultaneously from the effect of ribonucleic acids (catalytic action) and from the effect of substrates (mass action). This hypothesis explains cellular differentiation (multicellular organism) through constitutional variations of cytoplasmic ribonucleic acids. The writer's fundamental arguments come from the study of bacterial biology, especially from the study of mutations directed by principles of desoxyribonucleic nature.     

Investigation of Jacket Silhouette Based on Ease Distribution

The silhouette of women＇s garment is diversified in its design. In this paper,a new model was developed to predict the silhouette of jacket for the given girth measurements. Sixty-three princess-seam women＇s jackets with seven styles and nine girth dimensions of each style were produced. Their ease distribution was investigated at bustline,waistline,and hipline,respectively. The widths of the cross-sections for bustline,waistline,and hipline were formulated by multiple linear regressions. Then the silhouette was captured from the ratio of waist width to bust width of a designed jacket,together with that of waist width to hip width.     

Diving insects boost their buoyancy bubbles

Backswimmers (Notonectidae) are common diving insects found around the world that exploit the mid-water zone for predation--they breathe by using an air bubble collected at the surface. Here we show that backswimmers achieve prolonged periods of neutral buoyancy by using oxygen stored in their haemoglobin to stabilize the volume of the bubble as they breathe from it. This enables them to maintain their position in the water column without continually swimming.     

Glioma stem cells promote radioresistance by preferential activation of the DNA damage response

Ionizing radiation represents the most effective therapy for glioblastoma (World Health Organization grade IV glioma), one of the most lethal human malignancies, but radiotherapy remains only palliative because of radioresistance. The mechanisms underlying tumour radioresistance have remained elusive. Here we show that cancer stem cells contribute to glioma radioresistance through preferential activation of the DNA damage checkpoint response and an increase in DNA repair capacity. The fraction of tumour cells expressing CD133 (Prominin-1), a marker for both neural stem cells and brain cancer stem cells, is enriched after radiation in gliomas. In both cell culture and the brains of immunocompromised mice, CD133-expressing glioma cells survive ionizing radiation in increased proportions relative to most tumour cells, which lack CD133. CD133-expressing tumour cells isolated from both human glioma xenografts and primary patient glioblastoma specimens preferentially activate the DNA damage checkpoint in response to radiation, and repair radiation-induced DNA damage more effectively than CD133-negative tumour cells. In addition, the radioresistance of CD133-positive glioma stem cells can be reversed with a specific inhibitor of the Chk1 and Chk2 checkpoint kinases. Our results suggest that CD133-positive tumour cells represent the cellular population that confers glioma radioresistance and could be the source of tumour recurrence after radiation. Targeting DNA damage checkpoint response in cancer stem cells may overcome this radioresistance and provide a therapeutic model for malignant brain cancers.     

Eastern Pacific cooling and Atlantic overturning circulation during the last deglaciation

Surface ocean conditions in the equatorial Pacific Ocean could hold the clue to whether millennial-scale global climate change during glacial times was initiated through tropical ocean-atmosphere feedbacks or by changes in the Atlantic thermohaline circulation. North Atlantic cold periods during Heinrich events and millennial-scale cold events (stadials) have been linked with climatic changes in the tropical Atlantic Ocean and South America, as well as the Indian and East Asian monsoon systems, but not with tropical Pacific sea surface temperatures. Here we present a high-resolution record of sea surface temperatures in the eastern tropical Pacific derived from alkenone unsaturation measurements. Our data show a temperature drop of approximately 1 degrees C, synchronous (within dating uncertainties) with the shutdown of the Atlantic meridional overturning circulation during Heinrich event 1, and a smaller temperature drop of approximately 0.5 degrees C synchronous with the smaller reduction in the overturning circulation during the Younger Dryas event. Both cold events coincide with maxima in surface ocean productivity as inferred from 230Th-normalized carbon burial fluxes, suggesting increased upwelling at the time. From the concurrence of equatorial Pacific cooling with the two North Atlantic cold periods during deglaciation, we conclude that these millennial-scale climate changes were probably driven by a reorganization of the oceans' thermohaline circulation, although possibly amplified by tropical ocean-atmosphere interaction as suggested before.