Troublesome toxins: time to re-think plant-herbivore interactions in vertebrate ecology

Earlier models of plant-herbivore interactions relied on forms of functional response that related rates of ingestion by herbivores to mechanical or physical attributes such as bite size and rate. These models fail to predict a growing number of findings that implicate chemical toxins as important determinants of plant-herbivore dynamics. Specifically, considerable evidence suggests that toxins set upper limits on food intake for many species of herbivorous vertebrates. Herbivores feeding on toxin-containing plants must avoid saturating their detoxification systems, which often occurs before ingestion rates are limited by mechanical handling of food items. In light of the importance of plant toxins, a new approach is needed to link herbivores to their food base. We discuss necessary features of such an approach, note recent advances in herbivore functional response models that incorporate effects of plant toxins, and mention predictions that are consistent with observations in natural systems. Future ecological studies will need to address explicitly the importance of plant toxins in shaping plant and herbivore communities

CARD9 negatively regulates NLRP3-induced IL-1β production on Salmonella infection of macrophages.

Interleukin-1β (IL-1β) is a proinflammatory cytokine required for host control of bacterial infections, and its production must be tightly regulated to prevent excessive inflammation. Here we show that caspase recruitment domain-containing protein 9 (CARD9), a protein associated with induction of proinflammatory cytokines by fungi, has a negative role on IL-1β production during bacterial infection. Specifically, in response to activation of the nucleotide oligomerization domain receptor pyrin-domain containing protein 3 (NLRP3) by Salmonella infection, CARD9 negatively regulates IL-1β by fine-tuning pro-IL-1β expression, spleen tyrosine kinase (SYK)-mediated NLRP3 activation and repressing inflammasome-associated caspase-8 activity. CARD9 is suppressed during Salmonella enterica serovar Typhimurium infection, facilitating increased IL-1β production. CARD9 is, therefore, a central signalling hub that coordinates a pathogen-specific host inflammatory response.M.P. was supported by CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brazil). This work was supported by a grant from the BBSRC BB/K006436/1 and a Wellcome Trust Investigator award to CEB.This is the final version of the article. It first appeared from Nature Publishing Group via http://doi.org.10.1038/ncomms12874

Disponibilidad de recursos y defensas de las plantas frente al herbivorismo

Book ChapterEl grado de herbivorismo y la eficacia de las defensas muestran amplias variaciones en las especies de plantas. La disponibilidad de recursos en el ambiente se propone como el mayor determinante de la cantidad y tipo de defensas de las plantas. Cuando los recursos son limitados, las plantas de crecimiento lento inherente salen favorecidas, en comparacion con las de crecimiento acelerado; a su turno, las tasas lentas de crecimiento favorecen grandes inversiones en defensas para afrontar a los herbfvoros. La expectativa de vida de las hojas, que tambien depende de la disponibilidad de recursos, afecta las ventajas relativas de las defensas, con diferentes tasas de recambio. La restriccion relativa de diferentes recursos tambien restringe los tipos de defensas. Estas propuestas se comparan con otras teorfas sobre la evolucion de la defensa de las plantas

Modeling and Decoding Motor Cortical Activity Using a Switching Kalman Filter

We present a switching Kalman filter model for the real-time inference of hand kinematics from a population of motor cortical neurons. Firing rates are modeled as a Gaussian mixture where the mean of each Gaussian component is a linear function of hand kinematics. A "hidden state" models the probability of each mixture component and evolves over time in a Markov chain. The model generalizes previous encoding and decoding methods, addresses the non-Gaussian nature of firing rates, and can cope with crudely sorted neural data common in on-line prosthetic applications.Mathematic

3. Launching the New Enterprise

As the academic year of 1945-46 approached, the intensity of activity in preparation for actually opening the school in the fall term became overwhelming. Incredible though it may seem, Ives and Day were able in a period of a few weeks to assemble the nucleus of a faculty, several of whom formed a continuing source of counsel and advice both during the school’s formative years and thereafter. Includes: The First Dean and the School’s Dedication; A Participant’s View of the Early Years; Ives Moves On; Several Views of Martin P. Catherwood; The Founders

Spinach, a cyclops, and the search for a cure for prostate cancer

Abstract only availableOther than skin cancer, prostate cancer is the most prevalent form of cancer in men. The likelihood of developing prostate cancer increases with age; so that nearly every male will die with some form of prostate cancer though most likely not from the cancer itself. Prostate cancer is regulated by endocrine and dietary factors, as well as genetic predisposition. In the male reproductive tract, Sonic Hedgehog (Shh) signaling is necessary for the development of the prostate. It has also been found to be extremely important in the growth of a number of tumor types including prostate cancer, basal cell carcinoma (skin cancer), medulloblastoma, glioma, sarcoma, tumors of the digestive tract, small cell lung cancer and pancreatic carcinoma. The Lubahn lab has been studying the roles of Estrogen Receptors and estrogenic compounds on prostate cancer, and has recently used a series of phytoestrogens, natural estrogens found in plants, to inhibit the hedgehog-signaling pathway. One natural product, cyclopamine, is able to inhibit the pathway and has been shown to inhibit prostate cancer cell growth both in vitro and in vivo xenograft models. Additionally, some flavanoid compounds in spinach have been found to have a similar chemical structure to several other phytoestrogens that have been shown to have preventative effects on prostate cancer. A competitive binding assay was performed using various doses of cyclopamine and an unpurified spinach extract to determine Kd for both compounds to ER alpha and ER beta. The compounds were also tested in the NIH-3T3 Shh Light II cells, which have a stably transfected Gli-Luciferase reporter, to see if they downregulated the hedgehog signaling pathway.Food for the 21st Century Undergraduate Research Program in Nutritional Science

PHOTOCHEMISTRY OF PHYCOBILIPROTEINS

Native PEC from the cyanobacterium, Mastigocladus laminosus, and its isolated α-subunit show photoreversibly photochromic reactions with difference-maxima around 502 and 570 nm in the spectral region of the α-84 phycoviolobilin chromophore. (b) Native PEC and its β-subunit show little if any reversible photochemistry in the 600–620 nm region, where the phycocyanobilin chromophores on the β-subunit absorb maximally, (c) Reversible photochemistry is retained in ureadenatured PEC at pH = 7.0 or pH ≤ 3. The difference maxima are shifted to 510 and 600 nm, and the amplitudes are decreased. An irreversible absorbance increase occurs around 670 nm (pH ≤ 3). (d) The amplitude of the reversible photoreaction difference spectrum is maximum in the presence of 4–5 M urea or 1 M KSCN, conditions known to dissociate phycobiliprotein aggregates into monomers. At the same time, the phycocyanobilin chromophore(s) are bleached irreversibly, (e) The amplitude becomes very small in high aggregates, e.g. in phycobilisomes. (f) In a reciprocal manner, the phototransformation of native PEC leads to a reversible shift of its aggregation equilibrium between trimer and monomer. The latter is favored by orange, the former by green light, (g) It is concluded that the phycoviolobilin chromophore of PEC is responsible for reversible photochemistry in PEC, and that there is not only an influence of aggregation state on photochemistry, but also vice versa an effect of the status of the chromophore on aggregation state. This could constitute a primary signal in the putative function as sensory pigment, either directly, or indirectly via the release of other polypeptides, via photodynamic effects, or the like

Six Military and Patriotic Illustrated Songs. Elaborately Colored. In a novel form. Series No. 1.

This publication contains the lyrics to six songs, each accompanied by a color illustration, and an advertisement on the last page. 1. Our Grandfathers\u27 Days 2. The Captain with his Whiskers 3. Want — A Substitute 4. Dixie\u27s Land 5. Young American and ould Ireland 6. Kingdom Cominghttps://digitalcommons.wofford.edu/littlejohnmss/1325/thumbnail.jp

Inflammasome activation causes dual recruitment of NLRC4 and NLRP3 to the same macromolecular complex.

Pathogen recognition by nucleotide-binding oligomerization domain-like receptor (NLR) results in the formation of a macromolecular protein complex (inflammasome) that drives protective inflammatory responses in the host. It is thought that the number of inflammasome complexes forming in a cell is determined by the number of NLRs being activated, with each NLR initiating its own inflammasome assembly independent of one another; however, we show here that the important foodborne pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium) simultaneously activates at least two NLRs, whereas only a single inflammasome complex is formed in a macrophage. Both nucleotide-binding domain and leucine-rich repeat caspase recruitment domain 4 and nucleotide-binding domain and leucine-rich repeat pyrin domain 3 are simultaneously present in the same inflammasome, where both NLRs are required to drive IL-1β processing within the Salmonella-infected cell and to regulate the bacterial burden in mice. Superresolution imaging of Salmonella-infected macrophages revealed a macromolecular complex with an outer ring of apoptosis-associated speck-like protein containing a caspase activation and recruitment domain and an inner ring of NLRs, with active caspase effectors containing the pro-IL-1β substrate localized internal to the ring structure. Our data reveal the spatial localization of different components of the inflammasome and how different members of the NLR family cooperate to drive robust IL-1β processing during Salmonella infection.S.M.M was supported by a Cambridge International Scholarship. T.P.M was supported by a Wellcome Trust Research Career Development Fellowship (WT085090MA). This study was supported by Biotechnology and Biological Sciences Research Council (BBSRC) grants (BB/H003916/1 and BB/K006436/1) and a BBSRC Research Development Fellowship (BB/H021930/1) awarded to C.E.B.http://www.pnas.org/content/early/2014/05/05/1402911111.abstrac