Spectral variability of the particulate backscattering ratio

The spectral dependency of the particulate backscattering ratio is relevant in the fields of ocean color inversion, light field modeling, and inferring particle properties from optical measurements. Aside from theoretical predictions for spherical, homogeneous particles, we have very limited knowledge of the actual in situ spectral variability of the particulate backscattering ratio. This work presents results from five research cruises that were conducted over a three-year period. Water column profiles of physical and optical properties were conducted across diverse aquatic environments that offered a wide range of particle populations. The main objective of this research was to examine the behavior of the spectral particulate backscattering ratio in situ, both in terms of its absolute magnitude and its variability across visible wavelengths, using over nine thousand 1-meter binned data points for each of five wavelengths of the spectral particulate backscattering ratio. Our analysis reveals no spectral dependence of the particulate backscattering ratio within our measurement certainty, and a geometric mean value of 0.013 for this dataset. This is lower than the commonly used value of 0.0183 from Petzold\u27s integrated volume scattering data. Within the first optical depth of the water column, the mean particulate backscattering ratio was 0.010

Using remote sensing, in situ observations, and geographic information systems to map benthic habitats at Heceta Bank, Oregon

Dramatic declines in many species of demersal fishes off the West Coast have resulted in the designation of nine commercially important species as being overfished. While the causes of those declines are not clearly understood, the fact remains that a paucity of life history and abundance data exists for many demersal species, also known as groundfish. Due to this uncertainty, only 21 of the 82 species of groundfish managed under the Groundfish Fishery Management Plan of the Pacific Fishery Management Council (PFMC) have been fully assessed. One challenge in designing a systematic survey of groundfish resources is that many species associate with heterogeneous substrate of varying relief. In many areas, the rugosity of the substrata precludes sampling by conventional techniques (e.g. bottom trawl gear). This has stimulated research that characterizes fish-habitat associations for use in design of new survey methodology. Using a combination of remote sensing, in situ observations, and spatial analytical techniques, four benthic habitat classes were mapped for a large rocky bank off the central Oregon coast known as Heceta Bank. Observational data from human-occupied submersible and remotely operated vehicle dives in the late 1980s, 2000 and 2001 were used to establish habitat classes with specific substrate characteristics that have been statistically shown to correlate with demersal fish distributions. The observational habitat data was then extrapolated over the extent of a multibeam sonar survey conducted in 1998 using quantitative parameters derived from high-resolution bathymetric and backscatter imagery of the seafloor. The resultant map predicts the locations of four habitat classes: Ridge-Gully, High-Relief Rock (boulders, cobbles), Unconsolidated Sediment 1 (muds), and Unconsolidated Sediment 2 (sands). The main utility of the habitat map developed as part of the current study is that it provides a context for analyses of a variety of spatial data. For instance, habitat data provides one additional spatial component besides depth and latitude that can be used to stratify catch per unit effort data from surveys and commercial logbooks. Also, essential fish habitat for many demersal species can now be identified in more detail. Finally, habitat data like those presented here can aid in the design of marine reserves and protected areas by providing a context for spatial analyses of data of ecological importance

Forest Fragments as Barriers to Fruit Fly Dispersal: \u3ci\u3eAnastrepha\u3c/i\u3e (Diptera: Tephritidae) Populations in Orchards and Adjacent Forest Fragments in Puerto Rico

McPhail-type traps baited with ammonium acetate and putrescine were used to monitor populations of Anastrepha obliqua (Macquart) and Anastrepha suspensa(Loew) in two orchards with hosts of these flies (mango, Mangifera indica L., and carambola, Averrhoa carambola L.), as well as in forest fragments bordering these orchards. Contour maps were constructed to measure population distributions in and around orchards. Our results indicate that Anastrephapopulations are focused around host fruit in both space and time, that traps do not draw fruit flies away from hosts, even when placed within 15 m of the host, and that lures continue to function for 6 mo in the field. The contour mapping analyses reveal that populations of fruit flies are focused around ovipositional hosts. Although the trapping system does not have a very long effective sampling range, it is ideal, when used in combination with contour analyses, for assessing fine-scale (on the order of meters) population distributions, including identifying resources around which fly populations are focused or, conversely, assessing the effectiveness of management tools. The results are discussed as they pertain to monitoring and detecting Anastrepha spp. with the McPhail-type trap and ammonium acetate and putrescine baiting system and the dispersal of these flies within Puerto Rico

Planetary Dynamics and Habitable Planet Formation In Binary Star Systems

Whether binaries can harbor potentially habitable planets depends on several factors including the physical properties and the orbital characteristics of the binary system. While the former determines the location of the habitable zone (HZ), the latter affects the dynamics of the material from which terrestrial planets are formed (i.e., planetesimals and planetary embryos), and drives the final architecture of the planets assembly. In order for a habitable planet to form in a binary star system, these two factors have to work in harmony. That is, the orbital dynamics of the two stars and their interactions with the planet-forming material have to allow terrestrial planet formation in the habitable zone, and ensure that the orbit of a potentially habitable planet will be stable for long times. We have organized this chapter with the same order in mind. We begin by presenting a general discussion on the motion of planets in binary stars and their stability. We then discuss the stability of terrestrial planets, and the formation of potentially habitable planets in a binary-planetary system.Comment: 56 pages, 29 figures, chapter to appear in the book: Planets in Binary Star Systems (Ed. N. Haghighipour, Springer publishing company

Dendritic calcium signals in rhesus macaque motor cortex drive an optical brain-computer interface

Calcium imaging is a powerful tool for recording from large populations of neurons in vivo. Imaging in rhesus macaque motor cortex can enable the discovery of fundamental principles of motor cortical function and can inform the design of next generation brain-computer interfaces (BCIs). Surface two-photon imaging, however, cannot presently access somatic calcium signals of neurons from all layers of macaque motor cortex due to photon scattering. Here, we demonstrate an implant and imaging system capable of chronic, motion-stabilized two-photon imaging of neuronal calcium signals from macaques engaged in a motor task. By imaging apical dendrites, we achieved optical access to large populations of deep and superficial cortical neurons across dorsal premotor (PMd) and gyral primary motor (M1) cortices. Dendritic signals from individual neurons displayed tuning for different directions of arm movement. Combining several technical advances, we developed an optical BCI (oBCI) driven by these dendritic signalswhich successfully decoded movement direction online. By fusing two-photon functional imaging with CLARITY volumetric imaging, we verified that many imaged dendrites which contributed to oBCI decoding originated from layer 5 output neurons, including a putative Betz cell. This approach establishes new opportunities for studying motor control and designing BCIs via two photon imaging

MAVS-dependent host species range and pathogenicity of human hepatitis A virus

Although hepatotropic viruses are important causes of human disease, the intrahepatic immune response to hepatitis viruses is poorly understood due to a lack of tractable small animal models. Here we describe a murine model of hepatitis A virus (HAV) infection that recapitulates critical features of type A hepatitis in humans. We demonstrate that the capacity of HAV to evade MAVS-mediated type I interferon responses defines its host species range. HAV-induced liver injury was associated with interferon-independent intrinsic hepatocellular apoptosis and hepatic inflammation that unexpectedly results from MAVS and IRF3/7 signaling. This murine model thus reveals a previously undefined link between innate immune responses to virus infection and acute liver injury, providing a new paradigm for viral pathogenesis in the liver

Effects of Maternity Care Coordination on Pregnancy Outcomes: Propensity-Weighted Analyses

Care coordination services that link pregnant women to health-promoting resources, avoid duplication of effort, and improve communication between families and providers have been endorsed as a strategy for reducing disparities in adverse pregnancy outcomes, however empirical evidence regarding the effects of these services is contradictory and incomplete. This study investigates the effects of maternity care coordination on pregnancy outcomes in North Carolina

Inflammasomes Coordinate Pyroptosis and Natural Killer Cell Cytotoxicity to Clear Infection by a Ubiquitous Environmental Bacterium

Defective neutrophils in patients with chronic granulomatous disease (CGD) cause susceptibility to extracellular and intracellular infections. Microbes must first be ejected from intracellular niches to expose them to neutrophil attack, so we hypothesized that inflammasomes detect certain CGD pathogens upstream of neutrophil killing. Here, we identified one such ubiquitous environmental bacterium, Chromobacterium violaceum, whose extreme virulence was fully counteracted by the NLRC4 inflammasome. Caspase-1 protected via two parallel pathways that eliminated intracellular replication niches. Pyroptosis was the primary bacterial clearance mechanism in the spleen, but both pyroptosis and interleukin-18 (IL-18)-driven natural killer (NK) cell responses were required for liver defense. NK cells cleared hepatocyte replication niches via perforin-dependent cytotoxicity, whereas interferon-γ was not required. These insights suggested a therapeutic approach: exogenous IL-18 restored perforin-dependent cytotoxicity during infection by the inflammasome-evasive bacterium Listeria monocytogenes. Therefore, inflammasomes can trigger complementary programmed cell death mechanisms, directing sterilizing immunity against intracellular bacterial pathogens