Effect of acute copper sulfate exposure on olfactory responses to amino acids and pheromones in goldfish (Carassius auratus)

Exposure of olfactory epithelium to environmentally relevant concentrations of copper disrupts olfaction in fish. To examine the dynamics of recovery at both functional and morphological levels after acute copper exposure, unilateral exposure of goldfish olfactory epithelia to 100 μM CuSO4 (10 min) was followed by electro-olfactogram (EOG) recording and scanning electron microscopy. Sensitivity to amino acids (L-arginine and L-serine), generally considered food-related odorants, recovered most rapidly (three days), followed by that to catecholamines(3-O-methoxytyramine),bileacids(taurolithocholic acid) and the steroid pheromone, 17,20 -dihydroxy-4-pregnen- 3-one 20-sulfate, which took 28 days to reach full recovery. Sensitivity to the postovulatory pheromone prostaglandin F2R had not fully recovered even at 28 days. These changes in sensitivity were correlated with changes in the recovery of ciliated and microvillous receptor cell types. Microvillous cells appeared largely unaffected by CuSO4 treatment. Cilia in ciliated receptor neurones, however, appeared damaged one day post-treatment and were virtually absent after three days but had begun to recover after 14 days. Together, these results support the hypothesis that microvillous receptor neurones detect amino acids whereas ciliated receptor neurones were not functional and are responsible for detection of social stimuli (bile acidsandpheromones).Furthermore, differences in sensitivity to copper may be due to different transduction pathways in the different cell types

Spotting Trees with Few Leaves

We show two results related to the Hamiltonicity and $k$-Path algorithms in undirected graphs by Bj\"orklund [FOCS'10], and Bj\"orklund et al., [arXiv'10]. First, we demonstrate that the technique used can be generalized to finding some $k$-vertex tree with $l$ leaves in an $n$-vertex undirected graph in $O^*(1.657^k2^{l/2})$ time. It can be applied as a subroutine to solve the $k$-Internal Spanning Tree ($k$-IST) problem in $O^*(\min(3.455^k, 1.946^n))$ time using polynomial space, improving upon previous algorithms for this problem. In particular, for the first time we break the natural barrier of $O^*(2^n)$. Second, we show that the iterated random bipartition employed by the algorithm can be improved whenever the host graph admits a vertex coloring with few colors; it can be an ordinary proper vertex coloring, a fractional vertex coloring, or a vector coloring. In effect, we show improved bounds for $k$-Path and Hamiltonicity in any graph of maximum degree $\Delta=4,\ldots,12$ or with vector chromatic number at most 8

End-to-end verifiable elections in the standard model

We present the cryptographic implementation of “DEMOS”, a new e-voting system that is end-to-end verifiable in the standard model, i.e., without any additional “setup” assumption or access to a random oracle (RO). Previously known end-to-end verifiable e-voting systems required such additional assumptions (specifically, either the existence of a “randomness beacon” or were only shown secure in the RO model). In order to analyze our scheme, we also provide a modeling of end-to-end verifiability as well as privacy and receipt-freeness that encompasses previous definitions in the form of two concise attack games. Our scheme satisfies end-to-end verifiability information theoretically in the standard model and privacy/receipt-freeness under a computational assumption (subexponential Decisional Diffie Helman). In our construction, we utilize a number of techniques used for the first time in the context of e-voting schemes that include utilizing randomness from bit-fixing sources, zero-knowledge proofs with imperfect verifier randomness and complexity leveraging

Translating interdisciplinary knowledge for gender equity: Quantifying the impact of NSF ADVANCE

Background Interdisciplinarity is often hailed as a necessity for tackling real-world challenges. We examine the prevalence and impact of interdisciplinarity in the NSF ADVANCE program, which addresses gender equity in STEM. Methods Through a quantitative analysis of authorship, references, and citations in ADVANCE publications, we compare the interdisciplinarity of knowledge produced within the program to traditional disciplinary knowledge. We use Simpon's Diversity Index to test for differences across disciplines, and we use negative binomial regression to capture the potential influences of interdisciplinarity on the long-term impact of ADVANCE publications. Results ADVANCE publications exhibit higher levels of interdisciplinarity across three dimensions of knowledge integration, and cross-disciplinary ties within ADVANCE successfully integrate social science knowledge into diverse disciplines. Additionally, the interdisciplinarity of publication references positively influences the impact of ADVANCE work, while the interdisciplinarity of authorship teams does not. Conclusions These findings emphasize the significance of interdisciplinarity in problem-oriented knowledge production, indicating that specific forms of interdisciplinarity can lead to broader impact. By shedding light on the interplay between interdisciplinary approaches, disciplinary structures, and academic recognition, this article contributes to programmatic design to generate impactful problem-solving knowledge that also adds to the academic community

Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank

9 páginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved: the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and Conselleria de Pesca de la Xunta de GaliciaPeer reviewe

Fossils in Myanmar amber demonstrate the diversity of anti-predator strategies of Cretaceous holometabolan insect larvae

Holometabolan larvae are a major part of the animal biomass and an important food source for many animals. Many larvae evolved anti-predator strategies and some of these can even be recognized in fossils. A Lagerstätte known for well-preserved holometabolan larvae is the approximately 100-million-year-old Kachin amber from Myanmar. Fossils can not only allow to identify structural defensive specializations, but also lifestyle and even behavioral aspects. We review here the different defensive strategies employed by various holometabolan larvae found in Kachin amber, also reporting new cases of a leaf-mining hymenopteran caterpillar and a hangingfly caterpillar with extensive spines. This overview demonstrates that already 100 million years ago many modern strategies had already evolved in multiple lineages, but also reveals some cases of now extinct strategies. The repetitive independent evolution of similar strategies in distantly related lineages indicates that several strategies evolved convergently as a result of similar selective pressures

P2Y2 and P2Y6 receptor activation elicits intracellular calcium responses in human adipose-derived mesenchymal stromal cells

Adipose tissue contains self-renewing multipotent cells termed mesenchymal stromal cells. In situ, these cells serve to expand adipose tissue by adipogenesis, but their multipotency has gained interest for use in tissue regeneration. Little is known regarding the repertoire of receptors expressed by adipose-derived mesenchymal stromal cells (AD-MSCs). The purpose of this study was to undertake a comprehensive analysis of purinergic receptor expression. Mesenchymal stromal cells were isolated from human subcutaneous adipose tissue and confirmed by flow cytometry. The expression profile of purinergic receptors was determined by quantitative real-time PCR and immunocytochemistry. The molecular basis for adenine and uracil nucleotide-evoked intracellular calcium responses was determined using Fura-2 measurements. All the known subtypes of P2X and P2Y receptors, excluding P2X2, P2X3 and P2Y12 receptors, were detected at the mRNA and protein level. ATP, ADP and UTP elicited concentration-dependent calcium responses in mesenchymal cells (N = 7–9 donors), with a potency ranking ADP (EC50 1.3 ± 1.0 μM) > ATP (EC50 2.2 ± 1.1 μM) = UTP (3.2 ± 2.8 μM). Cells were unresponsive to UDP (< 30 μM) and UDP-glucose (< 30 μM). ATP responses were attenuated by selective P2Y2 receptor antagonism (AR-C118925XX; IC50 1.1 ± 0.8 μM, 73.0 ± 8.5% max inhibition; N = 7 donors), and UTP responses were abolished. ADP responses were attenuated by the selective P2Y6 receptor antagonist, MRS2587 (IC50 437 ± 133nM, 81.0 ± 8.4% max inhibition; N = 6 donors). These data demonstrate that adenine and uracil nucleotides elicit intracellular calcium responses in human AD-MSCs with a predominant role for P2Y2 and P2Y6 receptor activation. This study furthers understanding about how human adipose-derived mesenchymal stromal cells can respond to external signalling cues

Metal-to-Metal Distance Modulated Au(I)/Ru(II) Cyclophanyl Complexes : Cooperative Effects in Photoredox Catalysis

The modular synthesis of Au(I)/Ru(II) decorated mono- and heterobimetallic complexes with pi-conjugated [2.2]paracyclophane is described. [2.2]Paracyclophane serves as a rigid spacer which holds the metal centers in precise spatial orientations and allows metal-to-metal distance modulation. A broad set of architectural arrangements of pseudo -geminal, -ortho, -meta, and -para substitution patterns were employed. Metal-to-metal distance modulation of Au(I)/Ru(II) heterobimetallic complexes and the innate transannular pi-communication of the cyclophanyl scaffold provides a promising platform for the investigations of structure-activity relationship and cooperative effects. The Au(I)/Ru(II) heterobimetallic cyclophanyl complexes are stable, easily accessible, and exhibit promising catalytic activity in the visible-light promoted arylative Meyer-Schuster rearrangement.Peer reviewe

Histologische, funktionelle und spezifische Regeneration nach Durchtrennung der Fila olfactoria beim Goldfisch ( Carassius auratus )

1. Alter dissection of the olfactory libres (fila olfactoria, Fig. 1) in the goldfisch, histological (Fig. 5) as well as functional regeneration takes place. When regeneration of the olfactory fibres was complete, no differences in training and learning behaviour between operated and untreated control animals could be observed (Fig. 2). Specific regeneration could also be proved after dissection of the olfactory fibres: Preoperatively trained discriminative behaviour returned (Figs. 3, 4) when histological regeneration had reached an advanced state (Figs. 6, 7). Higher concentrations of all substances used for odour training were capable of exciting the taste receptors or other struktures outside the olfactory mucosa. The concentrations used for olfactory training, however, were below the thresholds for non-olfactory perception. Neither the surgical procedure nor the anesthesia influenced the memory function. 1. Goldfische können die durchschnittenen Bahnen der Fila olfactoria anatomisch und funktionell regenerieren.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47102/1/359_2004_Article_BF00340911.pd