pppA2’p5’A2’p5’A保护病毒感染细胞的普遍性

pppA2’p5’A2’p5’A(简称2’-5’P_3A_3)是干扰素作用于细胞后诱导产生的物质。干扰素的作用机理很复杂,其中之一是2’-5’寡聚腺苷酸合成酶的活力增加,此酶以ATP为底物合成2’-5’P_3A_3及其同系物2’-5’P_3An。但2’-5’P_3A_3或2’-5’P_3A_n本身是否具有抗病毒作用,干扰素的抗病毒作用是否通过2’-5’P_3A_3或2’-5’P_3An而进行,这是一个很     

A reciprocal translocation between ’Garfi’ almond and ’Nemared’ peach

A map with 51 markers (46 RFLPs and five isozymes) was constructed using an interspecific F₂ population between ’Garfi’ almond (Prunus amygdalus Batsch.) and ’Nemared’ peach [Prunus persica (L.) Batsch.]. This map was developed by selecting markers covering most of the distance of the eight linkage groups from previously constructed Prunus maps. The markers studied in this population mapped to seven linkage groups instead of the eight expected in Prunus. Markers belonging to groups 6 and 8 in previous maps formed a single group in the ’Garfi’×’Nemared’ F₂ and several marker pairs placed in different groups in other maps exhibited tight linkages. The study of pollen fertility and chromosome behavior during meiosis in the F₁ generation allowed us to confirm the hypothesis that a reciprocal translocation exists between ’Garfi’ and ’Nemared’. Based on independent evidence of linkage between markers and pollen fertility data in the F₂ population, we concluded that the breakpoint of the reciprocal translocation was placed between markers AC50 and AG26A in group 6 and between markers AG112A and FG230A in group 8. Received: 28 June 2000 / Accepted: 17 October 2000     

A note on ‘A generalized two-sex logistic model’

We re-visit the recently published paper on a generalization of the two-sex logistic model by Maxin and Sega [A generalized two-sex logistic model, J. Biol. Dyn. 7(1) (2013), pp. 302–318]. We show that the logistic assumption of a non-increasing birth rate can be replaced by a more general assumption of a non-increasing ratio between the female/male birth and mortality rate. In this note we indicate the changes necessary in the proofs of the theorems in [D. Maxin and L. Sega, A generalized two-sex logistic model, J. Biol. Dyn. 7(1) (2013), pp. 302–318] and discuss several situations where this new assumption is useful.     

A bird’s-eye view of autophagy

Autophagy is a process in which a eukaryotic (but not prokaryotic) cell destroys its own components through the lysosomal machinery. This tightly regulated process is essential for normal cell growth, development, and homeostasis, serving to maintain a balance between synthesis and degradation, resulting in the recycling of cellular products. Here we try to expand the concept of autophagy and define it as a general mechanism of regulation encompassing various levels of the biosphere. Interestingly, one of the consequences of such an approach is that we must presume an existence of the autophagic processes in the prokaryotic domain.     

A Beginner’s Guide to Phylogenetics

Metagenomics and the development of high throughput next generation sequencing capabilities have forced significant development in the field of phylogenetics: the study of the evolutionary relatedness of the planet’s inhabitants. Herein, I review the major tree-building strategies, challenges and opportunities which exist in this rapidly expanding field of evolutionary biology.     

A representative, highly informative ’genotyping set’ of barley SSRs

We have developed a ’genotyping set’ of 48 SSR-based genetic markers for application in genetical studies of barley. The SSRs are a subset of a collection of approximately 600 SSRs available to the barley research community. They have been specifically chosen according to the following criteria: (1) they are single locus; (2) their product quality is good under standard assay conditions; (3) they are distributed across the barley genome; and (4) they exhibit reasonably high polymorphic information content (PIC) values in the cultivated barley gene-pool. To maximise genotyping throughput, one of each SSR primer pair was 5′ end-labelled with either fam, hex or tet fluorochromes to allow automated data capture after running the samples on a DNA sequencer. SSR product sizes were assembled from a reference set of 24 barley genotypes which allowed the construction of ’graphical genotypes’ of each of the individual lines. The graphical genotypes provide a convenient tool for interrogating genetic similarity in the individuals surveyed. The product sizes were compared to those obtained from end-labelling one of the primers with ³³P and separating the products by denaturing PAGE followed by autoradiography. Although inconsistencies in size were common, they could generally be easily resolved. A reference manual for use of the ’genotyping set’ has been produced and is available as a PDF download file at http://www.scri.sari.ac.uk/ssr/pdf. These well-characterised barley SSRs, for the first time, provide a common set of robust PCR-based tools which can be used to integrate and compare information collected from fundamental and/or applied genetic studies on barley in different laboratories across the world. Received: 17 May 2000 / Accepted: 5 September 2000     

A Metabolic Study of Huntington’s Disease

Background

Huntington’s disease patients have a number of peripheral manifestations suggestive of metabolic and endocrine abnormalities. We, therefore, investigated a number of metabolic factors in a 24-hour study of Huntington’s disease gene carriers (premanifest and moderate stage II/III) and controls.

Methods

Control (n = 15), premanifest (n = 14) and stage II/III (n = 13) participants were studied with blood sampling over a 24-hour period. A battery of clinical tests including neurological rating and function scales were performed. Visceral and subcutaneous adipose distribution was measured using magnetic resonance imaging. We quantified fasting baseline concentrations of glucose, insulin, cholesterol, triglycerides, lipoprotein (a), fatty acids, amino acids, lactate and osteokines. Leptin and ghrelin were quantified in fasting samples and after a standardised meal. We assessed glucose, insulin, growth hormone and cortisol concentrations during a prolonged oral glucose tolerance test.

Results

We found no highly significant differences in carbohydrate, protein or lipid metabolism markers between healthy controls, premanifest and stage II/III Huntington’s disease subjects. For some markers (osteoprotegerin, tyrosine, lysine, phenylalanine and arginine) there is a suggestion (p values between 0.02 and 0.05) that levels are higher in patients with premanifest HD, but not moderate HD. However, given the large number of statistical tests performed interpretation of these findings must be cautious.

Conclusions

Contrary to previous studies that showed altered levels of metabolic markers in patients with Huntington’s disease, our study did not demonstrate convincing evidence of abnormalities in any of the markers examined. Our analyses were restricted to Huntington’s disease patients not taking neuroleptics, anti-depressants or other medication affecting metabolic pathways. Even with the modest sample sizes studied, the lack of highly significant results, despite many being tested, suggests that the majority of these markers do not differ markedly by disease status.     

A consensus ethnobotany of the Q’eqchi’ Maya of Southern Belize

An ethnobotany study in collaboration with Q’eqchi’ Maya healers of Southern Belize led to a collection of 169 medicinal plant species, belonging to 67 different families. The data show the use of a majority of species from primary or secondary semi-evergreen rainforests of Southern Belize, rather than weedy species. The medicinal uses of the plants were grouped into 17 usage categories. The frequency of use for each plant and the informant consensus factor for each usage category reveals a consensus among the healers on the use of plant species as well as on the diseases treated. These results suggest a well-defined medicinal tradition.     

A comment on ‘colonialism and ethnicity’

Self‐reported incidence of racial discrimination was investigated among four Asian‐American groups to explore their magnitude and the ways of coping with the discrimination episodes. The samples showed that among the two modes of coping ‐ problem‐focused or emotion‐focused coping ‐ a majority of Asian Americans has utilized the latter. Reasons of adopting these coping strategies were further explored for their determinants. Intergroup differences in ethnicity, education, gender and cultural values were found to exert influences on the ways of coping with racial discrimination among Asian Americans.     

A NEW SUBSPECIES OF PALLAS’S SQUIRREL

Callosciurus erythraeus wuliangshanensis Li et Wang Holotype: No 64032, male (ad.)August 2nd,1964,from Huangcaolin(alt. 1800m ), Mt. Wuliangshan, Yunnan. Paratypes: No. 067, male (ad.), November 2nd,1957; No 01,female(ad.), January 21st, 1957, both from Mt. Wuliangshan, Yunnan. Diagnosis: his race is much like C. e. michianus, except that its back has thick olive-brown, the midventral stripe and wedge stripe of the upper chest is olive-gray, without yellow, the extreme of the tail has a distinct black     

Pituitary Adenoma: A Clinician’S Perspective

ObjectiveTo review the underlying causes of pituitary lesions, a rational approach to their diagnosis, and therapeutic options.MethodsThe types of pituitary lesions and their clinical manifestations are reviewed, and treatment strategies and long-term follow-up are discussed.ResultsA pituitary adenoma is quite common and poses a challenge to the clinician to determine the clinical significance, the appropriate diagnosis, the need for treatment, and the appropriate therapy or therapies. The treatment of a pituitary adenoma depends on the type of tumor; a prolactinoma is treated medically with a dopamine agonist drug, and other lesions are usually treated by transsphenoidal surgical removal. Replacement of a deficient hormone or hormones is necessary for optimal functioning. Some patients require more than one treatment, including surgical intervention, replacement of a hormone or hormones, medications to lower hormone hypersecretion to normal (for prolactinoma, acromegaly, or Cushing disease), pituitary radiation therapy (optimally with focused irradiation such as the Gamma Knife or LINEAC), and, in the situation of persistent Cushing disease, bilateral adrenalectomy as a last resort. Lifelong monitoring is necessary for all these patients.ConclusionThe goal is to decrease the mass effect of the adenoma, to restore normal pituitary function, and to suppress hormone hypersecretion. Achievement of this goal necessitates the cooperation and interdisciplinary efforts of several medical specialties. (Endocr Pract. 2008;14:757-763)     

A specialist’s audit of aggregated occurrence records: An ‘aggregator’s’ perspective

A recent ZooKeys’ paper (Mesibov, 2013: http://www.pensoft.net/journal_home_page.php?journal_id=1&page=article&SESID=df7bcb35b02603283dcb83ee0e0af0c9&type=show&article_id=5111) has highlighted data quality issues in aggregated data sets, but did not provide a realistic way to address these issues. This paper provides an aggregator’s perspective including ways that the whole community can help to address data quality issues. The establishment of GBIF and national nodes (national aggregators) such as the Atlas of Living Australia (ALA) have integrated and exposed a huge diversity of biological observations along with many associated issues. Much of the admirable work by Mesibov (2013) was enabled by having the data exposed.Data quality, one of the highest priorities for GBIF, the national nodes and other aggregators, depends on both automatic methods and community experts to detect and correct data issues. Not all issues can however be automatically detected or corrected, so community assistance is needed to help improve the quality of exposed biological data. We do need to improve the infrastructure and associated processes to more easily identify data issues and document all changes to ensure a full record is permanently and publicly available.     

A critical note on ‘exclusive recognition’

Cenk Saracoglu conceptualizes the antipathy towards Kurdish migrants manifesting in certain cities of Turkey since the early 2000s as ‘exclusive recognition’ in his article ‘“Exclusive recognition”: the new dimensions of the question of ethnicity and nationalism in Turkey’ published in Ethnic and Racial Studies 32(4). According to the author, these recent developments represent ‘a historically specific ethnicization process’ and its sources cannot be found directly and only in historical discourses and policy of mainstream Turkish nationalism. In this note, I contradict the author's claims by asserting that the recent manifestations of anti-Kurdish sentiments are an extension of the ongoing policies of Turkish national identity based on Turkish nationalism.