Evolutionary mechanisms of habitat invasions, using the copepod Eurytemora affinis as a model system.

The study of the copepod Eurytemora affinis has provided unprecedented insights into mechanisms of invasive success. In this invited review, I summarize a subset of work from my laboratory to highlight key insights gained from studying E. affinis as a model system.

Spontaneous Neural Dynamics and Multi-scale Network Organization.

Spontaneous neural activity has historically been viewed as task-irrelevant noise that should be controlled for via experimental design, and removed through data analysis. However, electrophysiology and functional MRI studies of spontaneous activity patterns, which have greatly increased in number over the past decade, have revealed a close correspondence between these intrinsic patterns and the structural network architecture of functional brain circuits. In particular, by analyzing the large-scale covariation of spontaneous hemodynamics, researchers are able to reliably identify functional networks in the human brain.

Editorial: Stem Cell Engineering.

In recent years, the promise of stem cells as tools for basic research, in vitro diagnostics, and in vivo therapeutics is increasingly being realized. This Special issue of Biotechnology Journal explores recent advances in the emerging field of stem cell engineering, with a focus on applying engineering approaches to understanding stem cell biology and enabling translation of stem cells to commercial and clinical products.

Positron emission tomography imaging of CD105 expression in a rat myocardial infarction model with (64)Cu-NOTA-TRC105.

Biological changes following myocardial infarction (MI) lead to increased secretion of angiogenic factors that subsequently stimulate the formation of new blood vessels as a compensatory mechanism to reverse ischemia. The goal of this study was to assess the role of CD105 expression during MI-induced angiogenesis by positron emission tomography (PET) imaging using (64)Cu-labeled TRC105, an anti-CD105 monoclonal antibody. MI was induced by ligation of the left anterior descending (LAD) artery in female rats.

Pravastatin stimulates angiogenesis in a murine hindlimb ischemia model: a positron emission tomography imaging study with (64)Cu-NOTA-TRC105.

In this study, (64)Cu-NOTA-TRC105 (TRC105 is an anti-CD105 monoclonal antibody that binds to both human and murine CD105) positron emission tomography (PET) was used to assess the response to pravastatin treatment in a murine model of peripheral artery disease (PAD). Hindlimb ischemia was induced by ligation of the right femoral arteries in BALB/c mice under anesthesia, and the left hindlimb served as an internal control. Mice in the treatment group were given intraperitoneal pravastatin daily until the end of the study, whereas the animals in the control group were injected with 0.

Experience and generalization in a connectionist model of Mandarin Chinese relative clause processing.

Sentences containing relative clauses are well known to be difficult to comprehend, and they have long been an arena in which to investigate the role of working memory in language comprehension. However, recent work has suggested that relative clause processing is better described by ambiguity resolution processes than by limits on extrinsic working memory. We investigated these alternative views with a Simple Recurrent Network (SRN) model of relative clause processing in Mandarin Chinese, which has a unique pattern of word order across main and relative clauses and which has yielded mixed results in human comprehension studies.

Molecular MRI of VEGFR-2 reveals intra-tumor and inter-tumor heterogeneity.

Non-invasive and quantitative imaging of vascular endothelial growth factor receptor-2 (VEGFR-2) expression levels is highly important in cancer diagnosis, prognosis, and patient management. Although various literature reports have investigated the tumor expression levels of VEGFR-2 using imaging techniques such as positron emission tomography, single-photon emission computed tomography, targeted ultrasound, etc., accurate evaluation of the dynamic microdistribution of VEGFR-2 in vivo with good spatial and temporal resolution remains a major challenge.

Distinct spatial scale sensitivities for early categorization of faces and places: neuromagnetic and behavioral findings.

Research exploring the role of spatial frequencies in rapid stimulus detection and categorization report flexible reliance on specific spatial frequency (SF) bands. Here, through a set of behavioral and magnetoencephalography (MEG) experiments, we investigated the role of low spatial frequency (LSF) (<8 cycles/face) and high spatial frequency (HSF) (>25 cycles/face) information during the categorization of faces and places. Reaction time measures revealed significantly faster categorization of faces driven by LSF information, while rapid categorization of places was facilitated by HSF information.

Carbamoyl phosphate synthetase: a tunnel runs through it.

The direct transfer of metabolites from one protein to another in a biochemical pathway or between one active site and another within a single enzyme has been described as substrate channeling. The first structural visualization of such a phenomenon was provided by the X-ray crystallographic analysis of tryptophan synthase, in which a tunnel of approximately 25 A in length was observed. The recently determined three-dimensional structure of carbamoyl phosphate synthetase sets a new long distance record in that the three active sites are separated by nearly 100 A.

Minimal model systems for beta sheet secondary structure in proteins.

Use of model systems to explore the forces that control beta sheet formation was stymied for many years by the perception that small increments of beta sheet necessarily aggregate. Recently, however, a number of short peptides (9-16 residues in length) that fold into two-stranded antiparallel beta sheets ('beta hairpins') have been reported; several short peptides (20-24 residues in length) that fold into three-stranded antiparallel beta sheets have also been described. These model systems are beginning to provide fundamental insights into the origins of beta sheet conformational stability.

Neurogenic inflammation of Guinea-pig bladder.

Capsaicin, substance P, and ovalbumin, instilled into the bladders of naive and ovalbumin (OVA) sensitized guineapigs caused inflammation, as indicated by increased vascular permeability. Histological changes after exposure to these compounds progressed with time from intense vasodilatation to marginalization of granulocytes followed by interstitial migration of leukocytes. In vitro incubation of guinea-pig bladder tissue with substance P and ovalbumin stimulated release of prostaglandin D(2) and leukotrienes.