Investigation of noise analysis techniques for the MIT heavy water lattice

A reliable system for performing a Fourier analysis of a reactor noise signal has been constructed and utilized. Both auto- and cross-correlation techniques were used to study noise signals from the MITR hohlraum and the exponential lattice. As predicted by theory* the efficiency of the detectors used was insufficient to provide positive results. The lattice transfer function was electronically simulated and analyzed by the system confirming the reliability of the equipment. Several methods are suggested for increasing detector efficiencies to provide signal levels which will permit extraction of information about the kinetic behavior of the test lattice.http://www.archive.org/details/investigationofn00hau

Infrared astronomy

The decade of 1990's presents an opportunity to address fundamental astrophysical issues through observations at IR wavelengths made possible by technological and scientific advances during the last decade. The major elements of recommended program are: the Space Infrared Telescope Facility (SIRTF), the Stratospheric Observatory For Infrared Astronomy (SOFIA) and the IR Optimized 8-m Telescope (IRO), a detector and instrumentation program, the SubMilliMeter Mission (SMMM), the 2 Microns All Sky Survey (2MASS), a sound infrastructure, and technology development programs. Also presented are: perspective, science opportunities, technical overview, project recommendations, future directions, and infrastructure

The role of environmental, structural and anthropogenic variables on underpass use by African savanna elephants (Loxodonta africana) in the Tsavo Conservation Area

Wildlife crossing structures are effective interventions for mitigating fragmentation of habitats by linear infrastructure. The 2017 construction of a new railway cutting through the Tsavo Con- servation Area (TCA), home to the largest elephant population in Kenya, affected wildlife movement and habitat connectivity. Although numerous studies have investigated the use of wildlife crossing structures by a wide range of species, few have focused on their use by mega- herbivores. In this study, we examined use of 41 wildlife crossing structures by African savanna elephants (Loxodonta africana) along a 133 km section of new railway in Tsavo, Kenya. We used a generalized linear mixed modeling approach to assess the relationship between elephant crossing rate over 28 months between July 2017 to April 2021 and explanatory factors including crossing structure attributes, livestock presence and proximity to highways, water points and human settlement. We found that structural attributes of crossing structures were most strongly associ- ated with the elephant crossing rate, particularly height and its interaction with type of crossing structure (bridges, wildlife underpasses and culverts). Higher crossing structures were associated with higher crossing rate, with the largest influence of height at culverts and wildlife underpasses. Although bridges comprised only 19.5 % of the 41 available crossing structures, they accounted for a disproportionately high number of elephants crossing events (56 %). The results demon- strated the importance of bridges over designated crossing structures for elephants, with pre- dicted seasonal counts of elephant crossings being 0.31 for average sized culverts, 2.88 for wildlife underpasses and 5.86 for bridges. The environmental and anthropogenic variables were not strongly associated with elephant crossing rate. Our findings have direct application for future siting and design of crossing structures across elephant rang

Dietary Methionine Restriction Regulates Liver Protein Synthesis and Gene Expression Independently of Eukaryotic Initiation Factor 2 Phosphorylation in Mice

Background: The phosphorylation of eukaryotic initiation factor 2 (p-eIF2) during dietary amino acid insufficiency reduces protein synthesis and alters gene expression via the integrated stress response (ISR).Objective: We explored whether a Met-restricted (MR) diet activates the ISR to reduce body fat and regulate protein balance.Methods: Male and female mice aged 3-6 mo with either whole-body deletion of general control nonderepressible 2 (Gcn2) or liver-specific deletion of protein kinase R-like endoplasmic reticulum kinase (Perk) alongside wild-type or floxed control mice were fed an obesogenic diet sufficient in Met (0.86%) or an MR (0.12% Met) diet for ≤5 wk. Ala enrichment with deuterium was measured to calculate protein synthesis rates. The guanine nucleotide exchange factor activity of eIF2B was measured alongside p-eIF2 and hepatic mRNA expression levels at 2 d and 5 wk. Metabolic phenotyping was conducted at 4 wk, and body composition was measured throughout. Results were evaluated with the use of ANOVA (P < 0.05).Results: Feeding an MR diet for 2 d did not increase hepatic p-eIF2 or reduce eIF2B activity in wild-type or Gcn2-/- mice, yet many genes transcriptionally regulated by the ISR were altered in both strains in the same direction and amplitude. Feeding an MR diet for 5 wk increased p-eIF2 and reduced eIF2B activity in wild-type but not Gcn2-/- mice, yet ISR-regulated genes altered in both strains similarly. Furthermore, the MR diet reduced mixed and cytosolic but not mitochondrial protein synthesis in both the liver and skeletal muscle regardless of Gcn2 status. Despite the similarities between strains, the MR diet did not increase energy expenditure or reduce body fat in Gcn2-/- mice. Finally, feeding the MR diet to mice with Perk deleted in the liver increased hepatic p-eIF2 and altered body composition similar to floxed controls.Conclusions: Hepatic activation of the ISR resulting from an MR diet does not require p-eIF2. Gcn2 status influences body fat loss but not protein balance when Met is restricted

Fine Structure in the Circumstellar Environment of a Young, Solar-like Star: the Unique Eclipses of KH 15D

Results of an international campaign to photometrically monitor the unique pre-main sequence eclipsing object KH 15D are reported. An updated ephemeris for the eclipse is derived that incorporates a slightly revised period of 48.36 d. There is some evidence that the orbital period is actually twice that value, with two eclipses occurring per cycle. The extraordinary depth (~3.5 mag) and duration (~18 days) of the eclipse indicate that it is caused by circumstellar matter, presumably the inner portion of a disk. The eclipse has continued to lengthen with time and the central brightness reversals are not as extreme as they once were. V-R and V-I colors indicate that the system is slightly bluer near minimum light. Ingress and egress are remarkably well modeled by the passage of a knife-edge across a limb-darkened star. Possible models for the system are briefly discussed.Comment: 19 pages, 5 figure

Long‐lived Snell dwarf mice display increased proteostatic mechanisms that are not dependent on decreased mTORC1 activity

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111144/1/acel12329.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/111144/2/acel12329-sup-0001-SuppInfo.pd

Comparing silvopastoral systems and prospects in six regions of the world

Paper presented at the 12th North American Agroforesty Conference, which was held June 4-9, 2011 in Athens, Georgia.In Ashton, S. F., S.W. Workman, W.G. Hubbard and D.J. Moorhead, eds. Agroforestry: A Profitable Land Use. Proceedings, 12th North American Agroforestry Conference, Athens, GA, June 4-9, 2011.Silvopasture systems combine trees, forage and livestock in a variety of different species and management regimes, depending on the biophysical, economic, and social factors in a region. In some regions, culture and tradition cause producers to primarily focus on management of either the livestock and forage or the trees, while in other regions, the focus is on joint production. We describe and compare silvopastoral systems in six regions within five countries of the world: Misiones and Corrientes provinces, Argentina, La Pampa province, Argentina, the Southeast United States, the North Island of New Zealand, Paraguay and Uruguay. This summarizes the biological and social factors that have led to their adoption by farmers and the current status of these systems in each country.Frederick Cubbage (1), Gustavo Balmelli (2), Adriana Bussoni (3), Elke Noellemeyer (4), A. Pachas (5), Hugo Fassola (5), Luis Colcombet (5), Bel�n Rossner (5), Gregory Frey (6), Hayley Stevenson (1), James Hamilton (7) and William Hubbard (8) ; 1. Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, USA. 2. Instituto Nacional de Investigaci�n Agropecuaria, Tacuaremb�, Uruguay. 3. Universidad de la Rep�blica, Montevideo, Uruguay. 4. Universidad Nacional de La Pampa, Santa Rosa, La Pampa, Argentina. 5. INTA EEA Montecarlo, Montecarlo. Misiones, Argentina. 6. World Bank, Washington, D.C. 7. NC Cooperative Extension Service, Watauga County, Boone, North Carolina, USA. 8. Southern Regional Extension Forester, University of Georgia, Athens, Georgia, USA.Includes bibliographical references

Evidence of a North Atlantic right whale calf (Eubalaena glacialis) born in northeastern U.S. waters

Author Posting. © The Author(s), 2008. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Marine Mammal Science 25 (2009): 462-477, doi:10.1111/j.1748-7692.2008.00261.x.The general temporal and geographical patterns of North Atlantic right whale (Eubalaena glacialis) calving events have been clarified during the last quarter century of research (Kraus and Rolland 2007). Right whales give birth to a single calf every three to five years after a twelve- to thirteen-month gestation period (Best 1994; Kraus and Hatch 2001). Most calves are born between December and March in the coastal waters of the southeastern U.S., the only known calving ground for this species (Kraus et al. 2007; Winn et al. 1986). Although historical whaling records suggest that there were once two winter calving grounds, one off the southeastern U.S. and the other off northwestern Africa, it appears that only the former is still used today (Notarbartolo di Sciara et al. 1998; Reeves and Mitchell 1986; 1988). In the late winter, right whales leave the calving grounds and migrate to their foraging grounds off the northeastern U.S. and Canadian Maritimes. North Atlantic right whales can be found in Cape Cod and Massachusetts Bays throughout the late winter and early spring (Hamilton and Mayo 1990; Mayo and Marx 1990; Schevill et al. 1986), in the Great South Channel during mid-spring to early summer (Kenney et al. 1995), and in the Bay of Fundy (Kraus et al. 1982) and on the Scotian Shelf (Mitchell et al. 1986; Stone et al. 1988) during the summer and fall. Some individuals (mostly pregnant females and juveniles) return to the calving grounds off the southeastern U.S. in December and January, but the location of the rest of the population during those months is currently unknown (although recent evidence suggests that right whales are present in the Gulf of Maine and on the Scotian Shelf throughout the winter (Mellinger et al. 2007; T. Cole pers comm. ; S. Van Parijs pers comm. )

Transverse lipid organization dictates bending fluctuations in model plasma membranes

© 2020 The Royal Society of Chemistry. Membrane undulations play a vital role in many biological processes, including the regulation of membrane protein activity. The asymmetric lipid composition of most biological membranes complicates theoretical description of these bending fluctuations, yet experimental data that would inform any such a theory is scarce. Here, we used neutron spin-echo (NSE) spectroscopy to measure the bending fluctuations of large unilamellar vesicles (LUV) having an asymmetric transbilayer distribution of high- and low-melting lipids. The asymmetric vesicles were prepared using cyclodextrin-mediated lipid exchange, and were composed of an outer leaflet enriched in egg sphingomyelin (ESM) and an inner leaflet enriched in 1-palmitoyl-2-oleoyl-phosphoethanolamine (POPE), which have main transition temperatures of 37 °C and 25 °C, respectively. The overall membrane bending rigidity was measured at three temperatures: 15 °C, where both lipids are in a gel state; 45 °C, where both lipids are in a fluid state; and 30 °C, where there is gel-fluid co-existence. Remarkably, the dynamics for the fluid asymmetric LUVs (aLUVs) at 30 °C and 45 °C do not follow trends predicted by their symmetric counterparts. At 30 °C, compositional asymmetry suppressed the bending fluctuations, with the asymmetric bilayer exhibiting a larger bending modulus than that of symmetric bilayers corresponding to either the outer or inner leaflet. We conclude that the compositional asymmetry and leaflet coupling influence the internal dissipation within the bilayer and result in membrane properties that cannot be directly predicted from corresponding symmetric bilayers