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1. A solitary ground‐nesting wasp truncates its parental investment in response to detection of parasites

   https://doi.org/10.1111/een.12981  

   Rosenheim, Jay A. ( November 2020 , Ecological Entomology)

   Parental investment by solitary nest‐building wasps and bees is predicted to be plastic, responding to variation in the sex of the offspring, the availability of food used as provisions (‘resource limitation’), the female's inventory of mature oocytes (‘egg limitation’), and risk imposed by nest parasites.

   I observed nest provisioning byAmmophila dysmica, a solitary, ground‐nesting wasp that provisions its nest with one or two caterpillar prey to evaluate the hypotheses that provisioning is shaped by caterpillar size, offspring sex, the hunting time required to capture prey, a female's egg load, and penetration of nests by the parasitesArgochrysis armillaandHilarella hilarella.

   Ammophila dysmicawere more likely to add a second provision to the nest when the first prey item was relatively small and when provisioning daughters.

   Neither the hunting time required to capture the first caterpillar prey nor the female's inventory of oocytes predicted a female's likelihood of adding a second caterpillar to a nest. Variation in oocyte inventory across females was minimal; all females examined had a mature or nearly mature oocyte remaining in the ovaries immediately after laying an egg.

   Ammophila dysmicawere much less likely to add a second caterpillar to nests that were penetrated by parasites during the first provisioning.

   Although many nest parasites have evolved adaptations to avoid detection by their hosts, oviposition byA. armillaoften appears to reveal its presence, eliciting an abrupt truncation of investment by the host in that nest.

    

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2. A Rapid and Facile Purification Method for Glycan‐Binding Proteins and Glycoproteins

   https://doi.org/10.1002/cpps.113  

   Welch, Christina J. ; Kadav, Priyanka D. ; Edwards, Jared L. ; Krycia, Jessica ; Talaga, Melanie L. ; Bandyopadhyay, Purnima ; Dam, Tarun K. ( September 2020 , Current Protocols in Protein Science)

   Glycosylated proteins, namely glycoproteins and proteoglycans (collectively called glycoconjugates), are indispensable in a variety of biological processes. The functions of many glycoconjugates are regulated by their interactions with another group of proteins known as lectins. In order to understand the biological functions of lectins and their glycosylated binding partners, one must obtain these proteins in pure form. The conventional protein purification methods often require long times, elaborate infrastructure, costly reagents, and large sample volumes. To minimize some of these problems, we recently developed and validated a new method termed capture and release (CaRe). This method is time‐saving, precise, inexpensive, and it needs a relatively small sample volume. In this approach, targets (lectins and glycoproteins) are captured in solution by multivalent ligands called target capturing agents (TCAs). The captured targets are then released and separated from their TCAs to obtain purified targets. Application of the CaRe method could play an important role in discovering new lectins and glycoconjugates. © 2020 Wiley Periodicals LLC.

   Basic Protocol 1: Preparation of crude extracts containing the target proteins from soybean flour

   Alternate Protocol 1: Preparation of crude extracts from Jack bean meal

   Alternate Protocol 2: Preparation of crude extracts from the corms ofColocasia esculenta,Xanthosoma sagittifolium, and from the bulbs ofAllium sativum

   Alternate Protocol 3: Preparation ofEscherichia colicell lysates containing human galectin‐3

   Alternate Protocol 4: Preparation of crude extracts from chicken egg whites (source of ovalbumin)

   Basic Protocol 2: Preparation of 2% (v/v) red blood cell suspension

   Basic Protocol 3: Detection of lectin activity of the crude extracts

   Basic Protocol 4: Identification of multivalent inhibitors as target capturing agents by hemagglutination inhibition assays

   Basic Protocol 5: Testing the capturing abilities of target capturing agents by precipitation/turbidity assays

   Basic Protocol 6: Capturing of targets (lectins and glycoproteins) in the crude extracts by target capturing agents and separation of the target‐TCA complex from other components of the crude extracts

   Basic Protocol 7: Releasing the captured targets (lectins and glycoproteins) by dissolving the complex

   Basic Protocol 8: Separation of the targets (lectins and glycoproteins) from their respective target capturing agents

   Basic Protocol 9: Verification of the purity of the isolated targets (lectins or glycoproteins)

    

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3. Exosome Isolation by Ultracentrifugation and Precipitation and Techniques for Downstream Analyses

   https://doi.org/10.1002/cpcb.110  

   Coughlan, Christina ; Bruce, Kimberley D. ; Burgy, Olivier ; Boyd, Timothy D. ; Michel, Cole R. ; Garcia‐Perez, Josselyn E. ; Adame, Vanesa ; Anton, Paige ; Bettcher, Brianne M. ; Chial, Heidi J. ; et al ( July 2020 , Current Protocols in Cell Biology)

   Exosomes are 50‐ to 150‐nm‐diameter extracellular vesicles secreted by all mammalian cells except mature red blood cells and contribute to diverse physiological and pathological functions within the body. Many methods have been used to isolate and analyze exosomes, resulting in inconsistencies across experiments and raising questions about how to compare results obtained using different approaches. Questions have also been raised regarding the purity of the various preparations with regard to the sizes and types of vesicles and to the presence of lipoproteins. Thus, investigators often find it challenging to identify the optimal exosome isolation protocol for their experimental needs. Our laboratories have compared ultracentrifugation and commercial precipitation‐ and column‐based exosome isolation kits for exosome preparation. Here, we present protocols for exosome isolation using two of the most commonly used methods, ultracentrifugation and precipitation, followed by downstream analyses. We use NanoSight nanoparticle tracking analysis and flow cytometry (Cytek^®) to determine exosome concentrations and sizes. Imaging flow cytometry can be utilized to both size exosomes and immunophenotype surface markers on exosomes (ImageStream^®). High‐performance liquid chromatography followed by nano‐flow liquid chromatography–mass spectrometry (LCMS) of the exosome fractions can be used to determine the presence of lipoproteins, with LCMS able to provide a proteomic profile of the exosome preparations. We found that the precipitation method was six times faster and resulted in a ∼2.5‐fold higher concentration of exosomes per milliliter compared to ultracentrifugation. Both methods yielded extracellular vesicles in the size range of exosomes, and both preparations included apoproteins. © 2020 Wiley Periodicals LLC.

   Basic Protocol 1: Pre‐analytic fluid collection and processing

   Basic Protocol 2: Exosome isolation by ultracentrifugation

   Alternate Protocol 1: Exosome isolation by precipitation

   Basic Protocol 3: Analysis of exosomes by NanoSight nanoparticle tracking analysis

   Alternate Protocol 2: Analysis of exosomes by flow cytometry and imaging flow cytometry

   Basic Protocol 4: Downstream analysis of exosomes using high‐performance liquid chromatography

   Basic Protocol 5: Downstream analysis of the exosome proteome using nano‐flow liquid chromatography–mass spectrometry

    

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4. A rational map with infinitely many points of distinct arithmetic degrees

   https://doi.org/10.1017/etds.2019.30  

   LESIEUTRE, JOHN ; SATRIANO, MATTHEW ( January 2019 , Ergodic Theory and Dynamical Systems)

   Let be a dominant rational self-map of a smooth projective variety defined over $\overline{\mathbb{Q}}$ . For each point $P\in X(\overline{\mathbb{Q}})$ whose forward $f$ -orbit is well defined, Silverman introduced the arithmetic degree $\unicode[STIX]{x1D6FC}_{f}(P)$ , which measures the growth rate of the heights of the points $f^{n}(P)$ . Kawaguchi and Silverman conjectured that $\unicode[STIX]{x1D6FC}_{f}(P)$ is well defined and that, as $P$ varies, the set of values obtained by $\unicode[STIX]{x1D6FC}_{f}(P)$ is finite. Based on constructions by Bedford and Kim and by McMullen, we give a counterexample to this conjecture when $X=\mathbb{P}^{4}$ . 

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5. Abelian Covers of ℙ1 of p -Ordinary Ekedahl–Oort Type

   https://doi.org/10.1093/imrn/rnae241  

   Lin, Yuxin ; Mantovan, Elena ; Singhal, Deepesh ( October 2024 , International Mathematics Research Notices)

   Given a family of abelian covers of ${\mathbb{P}}^{1}$ and a prime $p$ of good reduction, by considering the associated Deligne–Mostow Shimura variety, we obtain non-trivial bounds for the Ekedahl–Oort types, and the Newton polygons, at prime $p$ for the curves in the family. In this paper, we investigate whether such bounds are sharp. In particular, we prove sharpness when the number of branching points is at most five and $p$ sufficiently large. Our result is a generalization under stricter assumptions of [ 2, Theorem 6.1] by Bouw, which proves the analogous statement for the $p$-rank, and it relies on the notion of Hasse–Witt triple introduced by Moonen in [ 12].

    

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