Queen-worker conflict over sex ratio: A comparison of primary and secondary sex ratios in the Argentine ant,Iridomyrmex humilis

We compare the primary sex ratio (proportion of haploid eggs laid by queens) and the secondary sex ratio (proportion of male pupae produced) in the Argentine ant Iridomyrmex humilis with the aim of investigating whether workers control the secondary sex ratio by selectively eliminating male brood. The proportion of haploid eggs produced by queens was close to 0.5 in late winter, decreased to less than 0.3 in spring and summer, and increased again to a value close to 0.5 in fall. Laboratory experiments indicate that temperture is a proximate factor influencing the primary sex ratio with a higher proportion of haploid eggs being laid at colder temperatures. Production of queen pupae ceased in mid-June, about three weeks before that of male pupae. After this time only worker pupae were produced. During the period of production of sexuals, the proportion of male pupae ranged from 0.30 to 0.38. Outside this period no males were reared although haploid eggs were produced all the year round by queens. Workers thus exert a control on the secondary sex ratio by eliminating a proportion of the male brood during the period of sexual production and eliminating all the males during the remainder of the cycle. These data are consistent with workers preferring a more female-biased sex ratio than queens. The evolutionary significance of the production of male eggs by queens all the year round is as yet unclear. It may be a mechanism allowing queen replacement in the case of the death of the queens in the colony.     

Chromosomal inversion discovered in C3H/HeJ mice

Mice of the inbred mouse strain C3H/HeJ have been shown to be homozygous for a chromosomal inversion on Chromosome (Chr) 6. The inversion encompasses about 20% of the chromosome from approximately 73 Mb to approximately 116 Mb. The importance of this finding is that linkage crosses using C3H/HeJ will show no recombination in this region of Chr 6. The inversion has no apparent effect on the phenotype of C3H/HeJ mice and its presence should not affect biological studies; however, use of C3H/HeJ mice for genetic analysis of Chr 6 should be avoided or the results interpreted with the inversion in mind. The inversion has been named In(6)1J (inversion Chr 6, Jackson 1).     

Monitoring the crystallization of amylose–lipid complexes during maize starch melting by synchrotron x‐ray diffraction

Most starch granules exhibit a natural crystallinity, with different diffraction patterns according to their botanical origin: A‐type from cereals and B‐type from tubers. The V polymorph results essentially from the complexing of amylose with compounds such as iodine, alcohols, or lipids. The intensity and nature of phase transitions (annealing, melting, polymorphic transitions, recrystallization, etc.) induced by hydrothermal treatments in crystalline structures are related to temperature and water content. Despite its small concentration, the lipid phase present mainly in cereal starches has a large influence on starch properties, particularly in complexing amylose. The formation of Vh crystalline structures was observed by synchrotron x‐ray diffraction in native maize starch heated at intermediate and high moisture contents (between 19 and 80%). For the first time, the crystallization of amylose–lipid complexes was evidenced in situ by x‐ray diffraction without any preliminary cooling, at heating rates corresponding to the usual conditions for differential scanning calorimetry experiments. For higher water contents, the crystallization of Vh complexes clearly occurred at 110–115°C. For intermediate water contents, mixed A + Vh (or B + Vh for high amylose starch) diffraction diagrams were recorded. Two mechanisms can be involved in amylose complexing: the first relating to crystallization of the amylose and lipid released during starch gelatinization, and the second to crystalline packing of separate complexed amylose chains (amorphous complexes) present in native cereal starches. © 1999 John Wiley & Sons, Inc. Biopoly 50: 99–110, 1999     

Antibodies directed against the peroxisomal targeting signal of firefly luciferase recognize multiple mammalian peroxisomal proteins

We have previously shown that the peroxisomal targeting signal in firefly luciferase consists of the COOH-terminal three amino acids of the protein, serine-lysine-leucine (Gould, S.J., G.A. Keller, N. Hosken, J. Wilkinson, and S. Subramani, 1989. J. Cell Biol. 108:1657-1664). Antibodies were raised against a synthetic peptide that contained this tripeptide at its COOH terminus. Immunofluorescence and immunocryoelectron microscopy revealed that the anti-peptide antibodies specifically detected peroxisomes in mammalian cells. Further characterization revealed that the antibodies were primarily directed against the COOH-terminal three amino acids of the peptide. In Western blot experiments, the antibodies recognized 15-20 rat liver peroxisomal proteins, but reacted with only a few proteins from other subcellular compartments. These results provide independent immunological evidence that the peroxisomal targeting signal identified in firefly luciferase is present in many peroxisomal proteins.     

Duty or dream? Edwin G. Conklin's critique of eugenics and support for American individualism

This paper assesses ideas about moral andreproductive duty in American eugenics duringthe early twentieth century. While extremeeugenicists, including Charles Davenport andPaul Popenoe, argued that social leaders andbiologists must work to prevent individuals whowere ``unfit' from reproducing, moderates,especially Edwin G. Conklin, presented adifferent view. Although he was sympathetic toeugenic goals and participated in eugenicorganizations throughout his life, Conklinrealized that eugenic ideas rarely could meetstrict scientific standards of proof. Withthis in mind, he did not restrict his eugenicvision to hereditary measures. Relying onhis experience as an embryologist, Conklininstead attempted to balance more extremeeugenic claims – that emphasized the absolutelimits posed by heredity – with his own view of``the possibilities of development.' Throughhis critique he argued that most human beingsnever even begin to approach their hereditarypotential; he moderated his own eugenicrhetoric so that it preserved individualopportunity and responsibility, or what hasoften been labeled the American Dream.     

Combination of a Proteomics Approach and Reengineering of Meso Scale Network Models for Prediction of Mode-of-Action for Tyrosine Kinase Inhibitors

In drug discovery, the characterisation of the precise modes of action (MoA) and of unwanted off-target effects of novel molecularly targeted compounds is of highest relevance. Recent approaches for identification of MoA have employed various techniques for modeling of well defined signaling pathways including structural information, changes in phenotypic behavior of cells and gene expression patterns after drug treatment. However, efficient approaches focusing on proteome wide data for the identification of MoA including interference with mutations are underrepresented. As mutations are key drivers of drug resistance in molecularly targeted tumor therapies, efficient analysis and modeling of downstream effects of mutations on drug MoA is a key to efficient development of improved targeted anti-cancer drugs. Here we present a combination of a global proteome analysis, reengineering of network models and integration of apoptosis data used to infer the mode-of-action of various tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML) cell lines expressing wild type as well as TKI resistance conferring mutants of BCR-ABL. The inferred network models provide a tool to predict the main MoA of drugs as well as to grouping of drugs with known similar kinase inhibitory activity patterns in comparison to drugs with an additional MoA. We believe that our direct network reconstruction approach, demonstrated on proteomics data, can provide a complementary method to the established network reconstruction approaches for the preclinical modeling of the MoA of various types of targeted drugs in cancer treatment. Hence it may contribute to the more precise prediction of clinically relevant on- and off-target effects of TKIs.     

Anaplastic thyroid cancer: outcomes of trimodal therapy

BackroundThe purpose of this study is to assess the impact of trimodal therapy [surgery, chemotherapy and external beam radiotherapy (EBRT)] in patients with anaplastic thyroid cancer (ATC) treated with curative intent.Materials and methodsRetrospective review of patients with ATC treated at a tertiary referral centre between January 2009 and June 2020. Data were collected regarding demographics, histology, staging, treatment and outcomes.ResultsSeven patients (4 female) were identified. Median age was 58 years (range 52–83 years). All patients received EBRT with concurrent doxorubicin. Six patients received surgery followed by chemoradiotherapy (CRT), and one underwent neoadjuvant CRT followed by surgery. Median radiological tumour size was 50mm (range 40–90 mm). Six patients had gross extrathyroidal extension and three had N1b disease. Prescribed radiotherapy schedules were 46.4 Gy in 29 bidaily fractions (n = 2, treated 2010), 60 Gy in 30 daily fractions (n = 2), 66 Gy in 30 fractions (n = 2) and 70 Gy in 35 fractions (n = 1; patient received neoadjuvant CRT). CRT was discontinued early for two patients due to toxicities. At median follow up of 5.8 months, 42.9% (3/7) patients were alive and disease-free. Only one patient developed a local failure. Three patients died from distant metastases without locoregional recurrence.ConclusionsDespite poor prognosis of ATC, selected patients with operable tumours may achieve high locoregional control rates with trimodal therapy, with possibility of long-term survival in select cases.     

Digital transformation—life cycle assessment of digital services,multifunctional devices and cloud computing

The International Journal of Life Cycle Assessment -