Effects of chloride on paramagnetic coupling of manganese in calcium chloride-washed photosystem II preparations

The effect of chloride on paramagnetic coupling of manganese in the oxygen-evolving complex of CaCl2--washed PS II preparations was examined using Q-band ESR. When these PS II preparations were depleted of chloride, a strong 6-line ESR signal characteristic of protein-bound, uncoupled manganese was observed. Incubation at high chloride concentrations caused the disappearance of this signal. By repeated removal and addition of chloride, the signal could be cycled on and off without loss of bound manganese. When in a chloride-depleted state, the ESR-detectable protein-bound manganese could be removed by treatment with EDTA. Subsequent heating of EDTA-treated preparations revealed a second pool of protein-bound manganese associated with PS II. One of these pools requires a high concentration of chloride to maintain paramagnetic coupling while the second pool (within the limits of our observations) does not appear to require chloride for the maintenance of the paramagnetically coupled state. © 1986

The HI and Ionized Gas Disk of the Seyfert Galaxy NGC 1144 = Arp 118: A Violently Interacting Galaxy with Peculiar Kinematics

We present observations of the distribution and kinematics of neutral and ionized gas in NGC 1144, a galaxy that forms part of the Arp 118 system. Ionized gas is present over a huge spread in velocity (1100 km/s) in the disk of NGC 1144, but HI emission is detected over only 1/3 of this velocity range, in an area that corresponds to the NW half of the disk. In the nuclear region of NGC 1144, a jump in velocity in the ionized gas component of 600 km/s is observed. Faint, narrow HI absorption lines are also detected against radio sources in the SE part of the disk of NGC 1144, which includes regions of massive star formation and a Seyfert nucleus. The peculiar HI distribution, which is concentrated in the NW disk, seems to be the inverse of the molecular distribution which is concentrated in the SE disk. Although this may partly be the result of the destruction of HI clouds in the SE disk, there is circumstantial evidence that the entire HI emission spectrum of NGC 1144 is affected by a deep nuclear absorption line covering a range of 600 km/s, and is likely blueshifted with respect to the nucleus. In this picture, a high column-density HI stream is associated with the nuclear ionized gas velocity discontinuity, and the absorption effectively masks any HI emission that would be present in the SE disk of NGC 1144.Comment: manuscript, arp118.ps: 28 pages; 1 Table: arp118.tab1.ps; 16 Figures: arp118.fig1-16.ps; Accepted to Ap

Monitoring Fish Diversity in Massies Creek, Ohio

Streams are susceptible to numerous threats to their water quality and biodiversity. In our region of southwest Ohio a major driver of these impacts is associated with current and past agricultural practices. These changes include straightening, embanking, dredging, and removal of large rocks and woody debris, increased erosion, and non-point source pollution. These structural and chemical impacts are known to significantly affect biodiversity in these streams. This means a greater understanding of stream ecology is of utter importance to places such as Greene County, Ohio due to the prevalence of agricultural practices in the landscape. In 2010 a 2.2 mile stream restoration project was completed by Greene County on the north fork of Massie’s Creek. Biological surveys and stream monitoring began in 2011 and extended on a regular basis through Fall 2014. In our study, conducted in the fall of 2014, we expanded the scope to evaluate fish biodiversity at previously studied sites as well as four additional sites within the watershed. Our objective was to collect data in order to draw comparisons between 2014 and previous year’s data including a study conducted in 1955 on Massie’s Creek. We sampled in six different locations, once in all six sites and twice in two specific sites. We used a mix of restored, unrestored, and unaltered stretches of stream as our sample locations. To determine diversity we used two different diversity indices: Shannon (H) and Simpson’s (D). Our Shannon value for the common unrestored site was 1.46 and our Simpson’s value was 0.33. Our Shannon value for the common restored site was 1.22 and our Simpson’s value was 0.36. Combining the data from the previous years with the 2014 data we found dominance to have decreased after restoration (which means there was more diversity)

Physical, Cardiovascular, & Metabolic Effects of Non-Exercise Weighted Vest Training

Introduction: The high prevalence of obesity and sedentary lifestyle contribute to the growing burden of health care costs, incidence of disease, and mortality, making a lifestyle that includes regular physical activity increasingly important. Low intensity resistance training has been studied as a possible intervention to increase physical activity in inactive individuals. Purpose: To determine the effects of a weighted vest treatment (WV) on steady state VO2, O2 deficit, VO2max, body mass index (BMI), and resting blood pressure (RBP). Methods: Fourteen college age women participated in a 4 week trial and completed both pre and posttest evaluations. These evaluations included a submaximal exercise bout, a maximal graded exercise test, determination of BMI, and measurement of RBP. Seven participants wore a weighted vest, fitted with 10% of their body weight, during normal daily activities for a minimum of 10 hours a day, 5 days each week. The remaining 7 participants served as a control group. ANCOVAs, with pretest measures serving as the covariates, were conducted to determine the effect of WV on posttest responses. Results: Mean (sd) pre-test O2 deficit values were 0.64 (0.18) and 0.68 (0.18) for the control and WV groups, respectively. Mean (sd) post-test O2 deficit values were 0.62 (0.15) and 0.38 (0.17) for the control and WV groups, respectively. Results of the ANCOVA revealed a significant effect of WV on O2 deficit with O2 deficit values being lower following WV (F(1,11) = 7.30, p = 0.02). Further, WV accounted for about 40% of the change observed in posttest O2 deficit values (ηp2 = 0.40). However, no significant effect of WV was seen on steady state VO2, VO2 max, BMI, or RBP. Conclusion: WV resulted in lower O2 deficit values suggesting that it could elicit training effects related to improved aerobic function. Possible explanations for the lack of effects on other variables could be related to the limitations imposed by the relatively small sample size and trial length. Future studies designed with larger sample sizes and longer trial periods might prove more effective in evaluating the effect of WV on eliciting health related benefits

Choice consequences: salinity preferences and hatchling survival in the mangrove rivulus (Kryptolebias marmoratus).

In heterogeneous environments, mobile species should occupy habitats in which their fitness is maximized. Mangrove rivulus fish inhabit mangrove ecosystems where salinities range from 0 to 65 ppt, but are most often collected from areas with salinities of ∼25 ppt. We examined the salinity preference of mangrove rivulus in a lateral salinity gradient, in the absence of predators and competitors. Fish could swim freely for 8 h throughout the gradient with chambers containing salinities ranging from 5 to 45 ppt (or 25 ppt throughout in the control). We defined preference as the salinity in which the fish spent most of their time, and also measured preference strength, latency to begin exploring the arena, and number of transitions between chambers. To determine whether these traits were repeatable, each fish experienced three trials. Mangrove rivulus spent a greater proportion of time in salinities lower (5-15 ppt) than they occupy in the wild. Significant among-individual variation in the (multivariate) behavioral phenotype emerged when animals experienced the gradient, indicating strong potential for selection to drive behavioral evolution in areas with diverse salinity microhabitats. We also showed that mangrove rivulus had a significantly greater probability of laying eggs in low salinities compared with control or high salinities. Eggs laid in lower salinities also had higher hatching success compared with those laid in higher salinities. Thus, although mangrove rivulus can tolerate a wide range of salinities, they prefer low salinities. These results raise questions about factors that prevent mangrove rivulus from occupying lower salinities in the wild, whether higher salinities impose energetic costs, and whether fitness changes as a function of salinity

Choice consequences: salinity preferences and hatchling survival in the mangrove rivulus (Kryptolebias marmoratus).

In heterogeneous environments, mobile species should occupy habitats in which their fitness is maximized. Mangrove rivulus fish inhabit mangrove ecosystems where salinities range from 0 to 65 ppt, but are most often collected from areas with salinities of ∼25 ppt. We examined the salinity preference of mangrove rivulus in a lateral salinity gradient, in the absence of predators and competitors. Fish could swim freely for 8 h throughout the gradient with chambers containing salinities ranging from 5 to 45 ppt (or 25 ppt throughout in the control). We defined preference as the salinity in which the fish spent most of their time, and also measured preference strength, latency to begin exploring the arena, and number of transitions between chambers. To determine whether these traits were repeatable, each fish experienced three trials. Mangrove rivulus spent a greater proportion of time in salinities lower (5-15 ppt) than they occupy in the wild. Significant among-individual variation in the (multivariate) behavioral phenotype emerged when animals experienced the gradient, indicating strong potential for selection to drive behavioral evolution in areas with diverse salinity microhabitats. We also showed that mangrove rivulus had a significantly greater probability of laying eggs in low salinities compared with control or high salinities. Eggs laid in lower salinities also had higher hatching success compared with those laid in higher salinities. Thus, although mangrove rivulus can tolerate a wide range of salinities, they prefer low salinities. These results raise questions about factors that prevent mangrove rivulus from occupying lower salinities in the wild, whether higher salinities impose energetic costs, and whether fitness changes as a function of salinity

Most lichens are rare, and degree of rarity is mediated by lichen traits and biotic partners

Aim Understanding ecological distributions of global biodiversity is stymied by incomplete knowledge of drivers of species rarity. These include trade-offs among life-history traits that impact dispersability, competition, reproductive output and speciation and extinction. In this study, we aim to understand potential drivers of rarity in North American lichens. Location and methods With nearly 5500 species and a third of global species richness, North America is a hotspot for lichen biodiversity. Here, we employ a continental-scale dataset on North American lichens to test potential drivers of species rarity. For all species, we determined coarse-scale geographical distribution along with the mode of reproduction, substrate, growth form and photobiont type. Results Our analyses found that most lichens are rare and known only from one or two ecoregions. Rare species are not equally distributed across ecoregions: the Eastern temperate hardwood forests and wet tropical forests of southern Florida harbour the vast majority of rare species. Wet to seasonally wet ecoregions of western North America are home to most remaining narrowly distributed lichen species. In contrast, northern ecoregions along with drier ecoregions including the Great Plains and deserts harbour primarily widespread species. Lichen rarity is significantly associated with species that live on bark or leaves, those with a Trentepohlia photobiont, those that are small, crustose and live closely appressed to their substrates, and those that reproduce sexually, dispersing only the mycobiont. North American lichens are represented unevenly across trait categories, with 65% of them having a crustose growth form, 73% bearing a Trebouxia or other green algal photobiont, 78% living on bark or rock and 77% reproducing sexually. Main conclusions Our study, spanning an entire continental-scale biota, helps to establish a generalized relationship among life-history traits and rarity in lichens and highlights the significance of biotic interactions in structuring biogeographical distributions. &nbsp;</p

Standing in a Garden of Forking Paths

According to the Path Principle, it is permissible to expand your set of beliefs iff (and because) the evidence you possess provides adequate support for such beliefs. If there is no path from here to there, you cannot add a belief to your belief set. If some thinker with the same type of evidential support has a path that they can take, so do you. The paths exist because of the evidence you possess and the support it provides. Evidential support grounds propositional justification. The principle is mistaken. There are permissible steps you may take that others may not even if you have the very same evidence. There are permissible steps that you cannot take that others can even if your beliefs receive the same type of evidential support. Because we have to assume almost nothing about the nature of evidential support to establish these results, we should reject evidentialism

Metacognition as Evidence for Evidentialism

Metacognition is the monitoring and controlling of cognitive processes. I examine the role of metacognition in ‘ordinary retrieval cases’, cases in which it is intuitive that via recollection the subject has a justified belief. Drawing on psychological research on metacognition, I argue that evidentialism has a unique, accurate prediction in each ordinary retrieval case: the subject has evidence for the proposition she justifiedly believes. But, I argue, process reliabilism has no unique, accurate predictions in these cases. I conclude that ordinary retrieval cases better support evidentialism than process reliabilism. This conclusion challenges several common assumptions. One is that non-evidentialism alone allows for a naturalized epistemology, i.e., an epistemology that is fully in accordance with scientific research and methodology. Another is that process reliabilism fares much better than evidentialism in the epistemology of memory