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71.
The paper aims at a pheno-climatic typology for Poland's mountainous and upland areas on macro- and mesoscales. The mean dates of sixty-three phenological events (period 1946–1965) were correlated with geographical and climatic parameters. Connections between phenophase dates during the vegetation period were also determined. The dates for beginning of blooming, and leafing of trees and shrubs, those of earing and blooming of corn, as well as the duration of some phenological periods were used as reference criteria. The spatial pattern of pheno-climatic types is shown on a map in the working scale 1500,000.Presented at the EigTH International Congress of Biometeorology, 9–14 September 1979, Shefayim, IsraËl.  相似文献   
72.
Circular Vicia faba (broad bean) chloroplast DNA was hybridized to the restriction fragment BamHI B from the DNA of the transducing phage lambda rifd18, which carries the Escherichia coli ribosomal RNA operon rrnB. Cytochrome spreadings of the heteroduplexes show homologies in the 16 S and 23 S rRNA regions, but none in the spacer. The same lambda rifd18 fragment was hybridized to the Vicia cpDNA 2SalI fragment 3, which contains the Vicia rBNA operon, resulting in an analogous heteroduplex configuration. Cytochrome spreadings of this heteroduplex in increasing concentrations of formamide reveal regions of incomplete homologies. Heteroduplexes between the E. coli rrnD operon, obtained from the recombinant plasmid pBK8, and circular Vicia cpDNA revealed homologies in the spacer region as well as in the 16 S and 23 S rRNA region. Hybrids between all three types of rDNA and their homologous rRNAs were prepared using the mica adsorption technique. They show that the 23 S, 16 S, and 5 S rRNAs are transcribed from the same strand of Vicia cpDNA. The positions of the rRNAs were measured and compared to the heteroduplex structure. It was observed that the E. coli rrnD operon in the plasmid pBK8 contains two 5 S rRNA sequences near the distal end.  相似文献   
73.
Artemisia packardiae from the Succor Creek area in southeastern Oregon is described and compared to its nearest relative,A. michauxiana Besser.  相似文献   
74.
75.
Summary The new highly sensitive method of fluorescamine reaction for the topochemical detection of primary amino groups was studied as a substitude of ninhydrin-Schiff's reaction for the localisation of total proteins in plant tissues. The influence of various coagulant and non-coagulatn fixatives on the induction of fluorescamine fluorescence was examined: ethanol, formaldehyde gas and solution, glutaraldehyde, acrolein, osmium tetroxide, Bouin, Rossman, Clarke and Zenker's fluids and FMA were employed. It was found that the use of the fluorogenic method is conditioned by the fixative ability to keep the amino groups disposable and by its capability to reduce the natural autofluorescence of plant material. A detailed account of the fixation methodology demonstrated that non-coagulant acrolein and coagulant mercuric chloride are the most promising fixatives for the use of the fluorescamine reaction in plant histochemistry.  相似文献   
76.
A qualitative and quantitative analysis of the plankton of two ponds in Kathmandu Valley (Nepal) was made. Vertical and seasonal variations of the plankton of one pond were studied as well as physical and chemical properties of the water (temperature, visibility, electrical conductivity, pH-value, alkalinity). During the dry winter the number of plankton species and individuals was low. In summer, before the onset of the monsoon mass developments of different μ-algae and Ceratium hirundinella occurred.  相似文献   
77.
BackgroundThe epidemiology of childhood SARS-CoV-2 infection and COVID-19-related illness remains little studied in high-transmission tropical settings, partly due to the less severe clinical manifestations typically developed by children and the limited availability of diagnostic tests. To address this knowledge gap, we investigate the prevalence and predictors of SARS-CoV-2 infection (either symptomatic or not) and disease in 5 years-old Amazonian children.Methodology/Principal findingsWe retrospectively estimated SARS-CoV-2 attack rates and the proportion of infections leading to COVID-19-related illness among 660 participants in a population-based birth cohort study in the Juruá Valley, Amazonian Brazil. Children were physically examined, tested for SARS-CoV-2 IgG and IgM antibodies, and had a comprehensive health questionnaire administered during a follow-up visit at the age of 5 years carried out in January or June-July 2021. We found serological evidence of past SARS-CoV-2 infection in 297 (45.0%; 95% confidence interval [CI], 41.2–48.9%) of 660 cohort participants, but only 15 (5.1%; 95% CI, 2.9–8.2%) seropositive children had a prior medical diagnosis of COVID-19 reported by their mothers or guardians. The period prevalence of clinically apparent COVID-19, defined as the presence of specific antibodies plus one or more clinical symptoms suggestive of COVID-19 (cough, shortness of breath, and loss of taste or smell) reported by their mothers or guardians since the pandemic onset, was estimated at 7.3% (95% CI, 5.4–9.5%). Importantly, children from the poorest households and those with less educated mothers were significantly more likely to be seropositive, after controlling for potential confounders by mixed-effects multiple Poisson regression analysis. Likewise, the period prevalence of COVID-19 was 1.8-fold (95%, CI 1.2–2.6-fold) higher among cohort participants exposed to food insecurity and 3.0-fold (95% CI, 2.8–3.5-fold) higher among those born to non-White mothers. Finally, children exposed to household and family contacts who had COVID-19 were at an increased risk of being SARS-CoV-2 seropositive and–even more markedly–of having had clinically apparent COVID-19 by the age of 5 years.Conclusions/SignificanceChildhood SARS-CoV-2 infection and COVID-19-associated illness are substantially underdiagnosed and underreported in the Amazon. Children in the most socioeconomically vulnerable households are disproportionately affected by SARS-CoV-2 infection and disease.  相似文献   
78.
Research needs a balance of risk‐taking in “breakthrough projects” and gradual progress. For building a sustainable knowledge base, it is indispensable to provide support for both. Subject Categories: Careers, Economics, Law & Politics, Science Policy & Publishing

Science is about venturing into the unknown to find unexpected insights and establish new knowledge. Increasingly, academic institutions and funding agencies such as the European Research Council (ERC) explicitly encourage and support scientists to foster risky and hopefully ground‐breaking research. Such incentives are important and have been greatly appreciated by the scientific community. However, the success of the ERC has had its downsides, as other actors in the funding ecosystem have adopted the ERC’s focus on “breakthrough science” and respective notions of scientific excellence. We argue that these tendencies are concerning since disruptive breakthrough innovation is not the only form of innovation in research. While continuous, gradual innovation is often taken for granted, it could become endangered in a research and funding ecosystem that places ever higher value on breakthrough science. This is problematic since, paradoxically, breakthrough potential in science builds on gradual innovation. If the value of gradual innovation is not better recognized, the potential for breakthrough innovation may well be stifled.
While continuous, gradual innovation is often taken for granted, it could become endangered in a research and funding ecosystem that places ever higher value on breakthrough science.
Concerns that the hypercompetitive dynamics of the current scientific system may impede rather than spur innovative research have been voiced for many years (Alberts et al, 2014). As performance indicators continue to play a central role for promotions and grants, researchers are under pressure to publish extensively, quickly, and preferably in high‐ranking journals (Burrows, 2012). These dynamics increase the risk of mental health issues among scientists (Jaremka et al, 2020), dis‐incentivise relevant and important work (Benedictus et al, 2016), decrease the quality of scientific papers (Sarewitz, 2016) and induce conservative and short‐term thinking rather than risk‐taking and original thinking required for scientific innovation (Alberts et al, 2014; Fochler et al, 2016). Against this background, strong incentives for fostering innovative and daring research are indispensable.  相似文献   
79.
Summary Linkage analysis has been carried out in six German families with autosomal dominantly inherited myotonia congenita (Thomsen's disease) using five chromosome 19 markers known to be linked to the gene for myotonic dystrophy (DM). Two of the markers, APOC1 and APOC2, are tightly linked to DM. Close linkage between these markers and myotonia congenita (MC) has been excluded to a distance of 9cM (z=-2.158). These data support the clinical suggestion that MC and DM are non-allelic disorders.  相似文献   
80.
Objective: To detect BRAF V600E mutation in thyroid fine-needle aspiration (FNA) slides and needle rinses (NR). Study Design: Tumor-enriched DNA was extracted from FNA smears, formalin-fixed paraffin-embedded (FFPE) sections, or NR specimens from 37 patients with confirmed papillary thyroid carcinoma or benign findings. An allele-specific primer selectively amplified the 1799 T>A BRAF mutation while simultaneously blocking amplification of wild-type (WT) BRAF with an unlabeled probe during PCR. Mutation detection was accomplished by melting analysis of the probe. Results: Allele-specific/blocking probe PCR confirmed the BRAF mutation status for 20 of 24 paired FNA/FFPE samples previously tested by fluorescent probe real-time PCR. For the other 4 cases, the sensitive PCR method detected the BRAF mutation in all paired FNA/FFPE samples. Previously, the mutation had been detected in only the FFPE samples. The BRAF mutation was also detected in some NR specimens. Conclusion: Treatment of patients with thyroid nodules is guided by FNA biopsy, which can be scantly cellular, necessitating a sensitive test that can detect low levels of BRAF V600E mutation in a WT background. We report increased detection of BRAF V600E in FNA specimens using allele-specific/blocking probe PCR, which has an analytical sensitivity of 0.01%.  相似文献   
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