The Shallow Benthic Invertebrate Recovery from the End-Cretaceous Mass Extinction across the Gulf Coastal Plain

The Gulf Coastal Plain, in the southeastern United States, contains several sites with well-preserved fossil assemblages from the Cretaceous- Paleogene boundary (K/Pg). Changes in benthic macroinvertebrate assemblages after mass extinction events commonly include reduction in body size of surviving organisms and preferential survival based on ecospace occupation. This study examines patterns of functional ecology and body size change in mollusk fossils from bulk samples collected throughout the post-extinction recovery interval at a well-studied boundary site from Darting Minnow Creek in Brazos, Texas USA and a recently described K/Pg boundary section on the Ouachita River in Malvern, Arkansas USA. The proportional abundance of mollusk ecological life modes at Malvern, AR shows a shift from an assemblage dominated by immobile, epifaunal suspension feeding oysters in the first 1.5 meters of the Paleogene to a community composed of mobile, infaunal, suspension and deposit-feeding bivalves. The change from a disaster assemblage to a recovery assemblage is consistent with previous community ecology studies documenting the recovery from the end-Cretaceous mass extinction. The shift in functional ecology is matched by a significant increase in bivalve body size and is interpreted as an increase in the available energy from primary productivity at this site. The disappearance of oysters suggests additional changes to the substrate, sedimentation, and/or freshwater input. Across the U.S. Gulf Coastal Plain, both sites show evidence of multiple stages in the recovery of diversity, ecological complexity, and body size of the benthic mollusk community in the aftermath of the K/Pg

The Barriers to Movement: The Effects of Anthropogenic Linear Features on the Space-Use Behaviors of Mule Deer and Pronghorn in Utah

Human development of structures like roads, fences, and other linear features can make it difficult for animals to move around their environment, affecting their ability to find food and avoid danger. Animal movement and the way they use space comes about from their responses to their surroundings and their choices to balance risk and reward. Because of this, we can understand how roads and fences affect wildlife by studying the way they move around their habitats. In this thesis, I focused on two large herbivores, mule deer and pronghorn, and studied how they use the space within Utah, United States of America. The goal of this research was to understand what the different effects of roads versus fences and road presence versus traffic on these species and their movements are. I found that fences and roads have different effects on pronghorn and mule deer and that the presence of roads itself versus the amount of traffic on the road affect animal behavior differently in different contexts. The results of this study can help wildlife managers to better understand how linear features impact animal movement and their behavior and make more informed decisions about how to protect wildlife in the Intermountain West

Intra-chain correlation functions and shapes of homopolymers with different architectures in dilute solution

We present results of Monte Carlo study of the monomer-monomer correlation functions, static structure factor and asphericity characteristics of a single homopolymer in the coil and globular states for three distinct architectures of the chain: ring, open and star. To rationalise the results we introduce the dimensionless correlation functions rescaled via the corresponding mean-squared distances between monomers. For flexible chains with some architectures these functions exhibit a large degree of universality by falling onto a single or several distinct master curves. In the repulsive regime, where a stretched exponential times a power law form (de Cloizeaux scaling) can be applied, the corresponding exponents $\delta$ and $\theta$ have been obtained. The exponent $\delta=1/\nu$ is found to be universal for flexible strongly repulsive coils and in agreement with the theoretical prediction from improved higher-order Borel-resummed renormalisation group calculations. The short-distance exponents $\theta_{\upsilon}$ of an open flexible chain are in a good agreement with the theoretical predictions in the strongly repulsive regime also. However, increasing the Kuhn length in relation to the monomer size leads to their fast cross-over towards the Gaussian behaviour. Likewise, a strong sensitivity of various exponents $\theta_{ij}$ on the stiffness of the chain, or on the number of arms in star polymers, is observed. The correlation functions in the globular state are found to have a more complicated oscillating behaviour and their degree of universality has been reviewed. Average shapes of the polymers in terms of the asphericity characteristics, as well as the universal behaviour in the static structure factors, have been also investigated.Comment: RevTeX 12 pages, 10 PS figures. Accepted by J. Chem. Phy

Infrasound from Volcanic Rockfalls

Proximal infrasound arrays can robustly track rapidly moving gravity-driven mass wasting, which occurs commonly at erupting volcanoes. This study reports on detection, localization, and quantification of frequent small rockfalls and infrequent pyroclastic density currents descending the southeast flanks of Santiaguito’s active Caliente Dome in January of 2014. Such activities are identified as moving sources, which descend several hundred meters at bulk flow speeds of up to ~10 m/s, which is considerably slower than the descent velocity of individual blocks. Infrasound rockfall signal character is readily distinguishable from explosion infrasound, which is manifested by a relatively fixed location source with lower frequency content. In contrast, the rockfalls of Santiaguito possess higher frequencies dominated by 7.5 to 20Hz energy. During our observation periods typical rockfall signals occurred ~10 times per hour and lasted tens of seconds or more. Array beamforming permitted detection of rockfall transients with amplitudes of only a few tens of millipascals that would be impossible to distinguish from noise using a single sensor. Conjoint time-synchronized video is used to corroborate location and to characterize various gravity-driven events

A field deployable method for a rapid screening analysis of inorganic arsenic in seaweed

The authors thank the support for getting the seaweed samples from the projects funded under the Department of Agriculture, Food and the Marine’s Competitive research programmes in Ireland. Reference number 14 SF 860. The authors thank Corny Brombach for the graphical abstract.Peer reviewedPublisher PD

Hematochezia in a patient with liver cirrhosis

Although commonly detectable in patients with cirrhosis, rectal varices only infrequently cause significant hematochezia (0.5–3.6%). While they may be expected to resolve with treatment of the concomitant portal hypertension, there is currently no standardized approach to their management in isolation. Therefore many authorities recommend transjugular intrahepatic portosystemic shunting (TIPS) as a means of alleviating otherwise recalcitrant bleeding. Conceptually, however, rectal varices should be as amenable to local therapies as are their counterparts occurring at the esophagogastric junction. In this report, we describe the use of endoscopic banding per ano to alleviate significant rectal bleeding in a patient with poorly controlled portal hypertension. This allowed medical optimisation so that the underlying pathology could be controlled without recourse to TIPS or other means of creating a formal portosystemic shunt

The effect of reciprocity priming on organ donor registration intentions and behavior

Background: Internationally the demand for organ transplants far exceeds the available supply of donated organs. Purpose: We examine if a digital reciprocity prime based on reciprocal altruism can be used to increase organ donor registration intentions and behavior. Methods: 420 participants (223 females) from England and Scotland aged 18+ who were not currently registered organ donors were randomized by block allocation using a 1:1 ratio to receive either a reciprocity prime or control message. After manipulation, they were asked to indicate their organ donation intentions and whether or not they would like to be taken to an organ donation registration and information page. Results: In line with our previous work, participants primed with a reciprocity statement reported greater intent to register as an organ donor than controls (using a 7-point Likert scale where higher scores = greater intention; prime mean = 4.3 (1.6) vs. control mean = 3.7 (1.4), P =< .001, d =0.4 [95%CI = 0.21-0.59]). There was again however, no effect on behavior as rates of participants agreeing to receive the donation register web-link were comparable between those primed at 11% (n= 23/210) [95%CI = 7.4-16.0] and controls at 12% (n= 25/210) [95%CI = 8.1-17.1], X²(1) = 0.09, p = .759. Conclusions: Reciprocal altruism appears useful for increasing intention towards joining the organ donation register. It does not however appear to increase organ donor behavior

On the order of a non-abelian representation group of a slim dense near hexagon

We show that, if the representation group $R$ of a slim dense near hexagon $S$ is non-abelian, then $R$ is of exponent 4 and $|R|=2^{\beta}$, $1+NPdim(S)\leq \beta\leq 1+dimV(S)$, where $NPdim(S)$ is the near polygon embedding dimension of $S$ and $dimV(S)$ is the dimension of the universal representation module $V(S)$ of $S$. Further, if $\beta =1+NPdim(S)$, then $R$ is an extraspecial 2-group (Theorem 1.6)