ALBERT

Description: Journal of the American Chemical Society DOI: 10.1021/jacs.5b12547

Description: Research Highlights: Regenerating northern white-cedar (Thuja occidentalis L.) is challenging throughout much of its range. This study attempts to relate differences in natural regeneration to stand- and seedbed-level factors. Background and Objectives: Lack of regeneration of northern white-cedar is often attributed to overbrowsing by white-tailed deer (Odocoileus virginianus Zimmerman) because white-cedar is a preferred winter browse species. However, there are many other factors that may contribute to regeneration failure for white-cedar including its specific seedbed requirements and competition from other, often faster-growing trees and shrubs. Materials and Methods: We surveyed five mature white-cedar stands in Wisconsin, USA that have had little to no management in the past 50+ years to find stem densities of natural white-cedar regeneration in three height classes. We also collected data at each stand on potential predictor variables including overstory attributes, competitive environment, seedbed, and browsing by deer. We used model selection to create separate models to predict stem density of each white-cedar regeneration height class. Results: None of the measures of deer browsing used in this study were found to be associated with white-cedar regeneration. Soil pH, competition from other seedlings and saplings, and stem density of white-cedar in the overstory were found to be potentially associated with white-cedar regeneration. Conclusions: While browsing by deer is likely a factor affecting white-cedar regeneration in many areas, this study highlights the challenge of quantifying deer browse effects, as well as showing that other factors likely contribute to the difficulty of regenerating white-cedar.

Description: The optimal combination of particle and tube size for simulation of a single tube of a wall-cooled multitubular Fischer-Tropsch (FT) reactor with cobalt as catalyst was determined. The maximum size of the tubes, realized without temperature runaway, enhances with increasing particle size until an optimal value is reached, thereby improving the production rate of liquid fuels per tube. Reasons for this are that heat transfer to the cooled tube wall for a given tube size is considerably enhanced by increasing the particle size and that the influence of pore diffusion on the effective rate of FT synthesis gets stronger with rising particle size, which reduces the temperature sensitivity of the reactor and decreases the danger of a temperature runaway. The simulations indicate that the use of FT eggshell catalysts is not an option for fixed-bed reactors. The temperature sensitivity of the reactor is strongly enhanced, which decreases the maximum tube size and with that the productivity per tube. All these effects are valid in general for wall-cooled fixed-bed reactors. Respective criteria are presented. With cobalt as catalyst, the optimal combination of particle size and tube size for simulation of a single tube of a wall-cooled multitubular Fischer-Tropsch reactor was established. The maximum size of the tubes, realized without temperature runaway, is improved with increasing particle size until an optimal value is reached, thereby improving the production rate of liquid fuels per tube.

Description: Simulation of a single tube of a wall-cooled multitubular Fischer-Tropsch (FT) reactor with a cobalt catalyst indicates that the reactor performance is improved by enlarging the catalyst particle diameter. This aspect is studied for variation of the particle size for a fixed tube diameter and vice versa. For a syngas conversion per pass of about 30 % as target and a typical industrially used single-tube diameter of 40 mm, a particle size of 〉 3 mm is appropriate with regard to a high production rate of higher hydrocarbons. For a particle diameter of 〈 3 mm, a temperature runaway can only be avoided by rather low cooling temperatures, and the target conversion cannot be reached. In addition, the pressure drop then gets rather high. The reasons for this behavior are: (i) the heat transfer to the cooled tube wall for a given tube size is considerably enhanced by increasing the particle size; (ii) the influence of pore diffusion on the effective rate gets stronger with rising particle size which decreases the danger of temperature runaway. Detailed simulation of the influence of the catalyst particle size on the behavior of a multitubular Fischer-Tropsch reactor with regard to syngas conversion and production rate of hydrocarbons per tube in a wall-cooled single tube with cobalt as catalyst indicates that the reactor performance is improved by enlarging the catalyst particle diameter. Reasons for this unexpected behavior are evaluated.

Description: Analytical Chemistry DOI: 10.1021/ac503933t

Description: To provide context for the diversification of archosaurs--the group that includes crocodilians, dinosaurs, and birds--we generated draft genomes of three crocodilians: Alligator mississippiensis (the American alligator), Crocodylus porosus (the saltwater crocodile), and Gavialis gangeticus (the Indian gharial). We observed an exceptionally slow rate of genome evolution within crocodilians at all levels, including nucleotide substitutions, indels, transposable element content and movement, gene family evolution, and chromosomal synteny. When placed within the context of related taxa including birds and turtles, this suggests that the common ancestor of all of these taxa also exhibited slow genome evolution and that the comparatively rapid evolution is derived in birds. The data also provided the opportunity to analyze heterozygosity in crocodilians, which indicates a likely reduction in population size for all three taxa through the Pleistocene. Finally, these data combined with newly published bird genomes allowed us to reconstruct the partial genome of the common ancestor of archosaurs, thereby providing a tool to investigate the genetic starting material of crocodilians, birds, and dinosaurs.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4386873/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4386873/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Green, Richard E -- Braun, Edward L -- Armstrong, Joel -- Earl, Dent -- Nguyen, Ngan -- Hickey, Glenn -- Vandewege, Michael W -- St John, John A -- Capella-Gutierrez, Salvador -- Castoe, Todd A -- Kern, Colin -- Fujita, Matthew K -- Opazo, Juan C -- Jurka, Jerzy -- Kojima, Kenji K -- Caballero, Juan -- Hubley, Robert M -- Smit, Arian F -- Platt, Roy N -- Lavoie, Christine A -- Ramakodi, Meganathan P -- Finger, John W Jr -- Suh, Alexander -- Isberg, Sally R -- Miles, Lee -- Chong, Amanda Y -- Jaratlerdsiri, Weerachai -- Gongora, Jaime -- Moran, Christopher -- Iriarte, Andres -- McCormack, John -- Burgess, Shane C -- Edwards, Scott V -- Lyons, Eric -- Williams, Christina -- Breen, Matthew -- Howard, Jason T -- Gresham, Cathy R -- Peterson, Daniel G -- Schmitz, Jurgen -- Pollock, David D -- Haussler, David -- Triplett, Eric W -- Zhang, Guojie -- Irie, Naoki -- Jarvis, Erich D -- Brochu, Christopher A -- Schmidt, Carl J -- McCarthy, Fiona M -- Faircloth, Brant C -- Hoffmann, Federico G -- Glenn, Travis C -- Gabaldon, Toni -- Paten, Benedict -- Ray, David A -- 1U41HG006992-2/HG/NHGRI NIH HHS/ -- 1U41HG007234-01/HG/NHGRI NIH HHS/ -- 5U01HG004695/HG/NHGRI NIH HHS/ -- R01 HG002939/HG/NHGRI NIH HHS/ -- U41 HG006992/HG/NHGRI NIH HHS/ -- Howard Hughes Medical Institute/ -- New York, N.Y. -- Science. 2014 Dec 12;346(6215):1254449. doi: 10.1126/science.1254449. Epub 2014 Dec 11.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA. ed@soe.ucsc.edu david.a.ray@ttu.edu. ; Department of Biology and Genetics Institute, University of Florida, Gainesville, FL 32611, USA. ; Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA. Center for Biomolecular Science and Engineering, University of California, Santa Cruz, CA 95064, USA. ; Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA. ; Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA. ; Bioinformatics and Genomics Programme, Centre for Genomic Regulation, 08003 Barcelona, Spain. Universitat Pompeu Fabra, 08003 Barcelona, Spain. ; Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA. Department of Biology, University of Texas, Arlington, TX 76019, USA. ; Department of Computer and Information Sciences, University of Delaware, Newark, DE 19717, USA. ; Department of Biology, University of Texas, Arlington, TX 76019, USA. ; Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile. ; Genetic Information Research Institute, Mountain View, CA 94043, USA. ; Institute for Systems Biology, Seattle, WA 98109, USA. ; Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA. Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA. ; Department of Environmental Health Science, University of Georgia, Athens, GA 30602, USA. ; Institute of Experimental Pathology (ZMBE), University of Munster, D-48149 Munster, Germany. Department of Evolutionary Biology (EBC), Uppsala University, SE-752 36 Uppsala, Sweden. ; Porosus Pty. Ltd., Palmerston, NT 0831, Australia. Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia. Centre for Crocodile Research, Noonamah, NT 0837, Australia. ; Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia. ; Departamento de Desarrollo Biotecnologico, Instituto de Higiene, Facultad de Medicina, Universidad de la Republica, Montevideo, Uruguay. ; Moore Laboratory of Zoology, Occidental College, Los Angeles, CA 90041, USA. ; College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85721, USA. ; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA. ; School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA. ; Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC 27607, USA. ; Howard Hughes Medical Institute, Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA. ; Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA. ; Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA. Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, MS 39762, USA. ; Institute of Experimental Pathology (ZMBE), University of Munster, D-48149 Munster, Germany. ; Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA. ; Center for Biomolecular Science and Engineering, University of California, Santa Cruz, CA 95064, USA. Howard Hughes Medical Institute, Bethesda, MD 20814, USA. ; Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA. ; China National GeneBank, BGI-Shenzhen, Shenzhen, China. Center for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark. ; Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, Japan. ; Department of Earth and Environmental Sciences, University of Iowa, Iowa City, IA 52242, USA. ; Department of Animal and Food Sciences, University of Delaware, Newark, DE 19717, USA. ; School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ 85721, USA. ; Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90019, USA. Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA. ; Bioinformatics and Genomics Programme, Centre for Genomic Regulation, 08003 Barcelona, Spain. Universitat Pompeu Fabra, 08003 Barcelona, Spain. Institucio Catalana de Recerca i Estudis Avancats, 08010 Barcelona, Spain. ; Center for Biomolecular Science and Engineering, University of California, Santa Cruz, CA 95064, USA. ; Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA. Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA. Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA. ed@soe.ucsc.edu david.a.ray@ttu.edu.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25504731" target="_blank"〉PubMed〈/a〉

Description: In many social species, groups of animals defend a shared territory against rival conspecifics. Intruders can be detected from a variety of cues, including fecal deposits, and the strength of response is expected to vary depending on the identity of the rival group. Previous studies examining differences in response to neighbor and stranger groups have focused on the immediate response to the relevant cues. Here, we investigated how simulated intrusions of rival groups affect both immediate responses and postinspection movement patterns. To do so, we used a fecal translocation experiment at latrine sites within the territories of dwarf mongoose Helogale parvula groups. Immediate responses were adjusted to the level of threat, with greater scent-marking behavior, time spent at the latrine, and group-member participation when groups were presented with fecal matter from out-group rivals relative to control (own group and herbivore) feces. Subsequent movement of the group was also affected by threat level, with a decrease in speed and distance covered following simulated intrusions by out-group rivals compared with control conditions. However, there were no significant differences in immediate responses or post-latrine movement patterns when comparing simulated neighbor and stranger intrusions. These results indicate that territorial intrusions can elicit not just an immediate change in behavior but more far-reaching consequences in terms of movement dynamics. They also raise the possibility that neighbor–stranger discrimination predictions are not necessarily as clear-cut as previously described.

Description: Forests around the world are experiencing increasingly severe droughts and elevated competitive intensity due to increased tree density. However, the influence of interactions between drought and competition on forest growth remains poorly understood. Using a unique dataset of stand-scale dendrochronology sampled from 6405 trees, we quantified how annual growth of entire tree populations responds to drought and competition in eight, long-term (multi-decadal), experiments with replicated levels of density (e.g., competitive intensity) arrayed across a broad climatic and compositional gradient. Forest growth (cumulative individual tree growth within a stand) declined during drought, especially during more severe drought in drier climates. Forest growth declines were exacerbated by high density at all sites but one, particularly during periods of more severe drought. Surprisingly, the influence of forest density was persistent overall, but these density impacts were greater in the humid sites than in more arid sites. Significant density impacts occurred during periods of more extreme drought, and during warmer temperatures in the semi-arid sites but during periods of cooler temperatures in the humid sites. Because competition has a consistent influence over growth response to drought, maintaining forests at lower density may enhance resilience to drought in all climates.