Phytoplankton species composition and abundance in a Gulf Stream warm core ring. I. Changes over a five month period

During the spring and summer of 1982, Gulf Stream warm core ring (WCR) 82B was sampled during four cruises from April to August to investigate the changes in the phytoplankton flora with time. Discrete water samples from 28 stations were collected for identification and enumeration of phytoplankton. The spring increase in WCR 828 occurred from late April to mid-May and was multiphasic; early periods were dominated by the diatoms Minidiscus trioculatus (4–5 μm diam.) and a small Thalassiosira, possibly T. bulbosa, while later periods were dominated by a small (2–3 μm) biflagellate. In June, another diatom concentration was detected at ring center, but this one was dominated by Chaetoceros cf. vixvisibilis and Leptocylindrus danicus. After interactions with and overwashes by the Gulf Stream and Slope Water in July, diatom numbers in the surface waters of the ring in August were greatly reduced relative to June, and no single species dominated. Changes in phytoplankton abundance in the ring core occurred on different time sequences from changes in the surrounding Slope Water or in the source water, the Sargasso Sea. The dominant taxa in the ring changed rapidly, on time scales of 1.5 months or less (intercruise time period). Successional changes were more important in altering the phytoplankton composition during the first two cruises, while sequential changes characterized the end of the study period. The ring center showed dramatic differences from its source water just 2 months after ring formation but remained distinct from the Slope Water for 4–5 months

Phytoplankton species composition and abundance in a Gulf Stream warm core ring. II. Distributional patterns

During the spring and summer of 1982, Gulf Stream warm core ring (WCR) 82B was sampled during four cruises from April to August to investigate phytoplankton distributional patterns. Discrete water samples from 28 stations were collected for identification and enumeration of phytoplankton. In April, when the water column was well mixed to 350 m, quantitative samples clustered by station when the 100 most frequently observed taxa were used as variables, indicating fairly unique assemblages at each station that were consistent with depth. Two transects across the ring in June showed a symmetrical diatom abundance maximum, dominated by Chaetoceros cf. vixvisibilis (maximum abundance 31,900 cells l–1) and Leptocylindrus danicus (maximum abundance 21,000 cells l–1), situated in the surface water at ring center. Dinoflagellate and coccolithophorid maxima were situated slightly deeper than the diatom maximum, in the seasonal thermocline from 20 to 35 m. A biomass maximum observed in a Shelf Water entrainment feature wrapping around the eastern perimeter of the ring contained elevated numbers of coccolithophorids and coccoid, unicellular monads (1–3 μm in diameter) and was thus compositionally distinct from the ring center biomass maximum. In July and August the ring underwent numerous interactions with and overwashes by the Slope Water and Gulf Stream. August samples from the ring, Sargasso Sea, Gulf Stream, and Slope Water all contained similar taxa and abundances. Different phytoplankton groups may be responding to different nutrient input mechanisms at the ring edge and center. Diatom maxima at ring center may form as a result of pulsed nutrient input from storms and a slight upwelling due to the gradual relaxation of the thermocline as the ring ages, while concentrations of ultraplanktonic algae (monads, coccolithophorids) toward the ring margin may result from near steady-state nutrient input along sloping isopycnals and/or advection from the ring exterior

Size Distributions of Coastal Ocean Suspended Particulate Inorganic Matter: Amorphous Silica and Clay Minerals and their Dynamics

Particulate inorganic matter (PIM) is a key component in estuarine and coastal systems and plays a critical role in trace metal cycling. Better understanding of coastal dynamics and biogeochemistry re-quires improved quantification of PIM in terms of its concentration, size distribution, and mineral species composition. The angular pattern of light scattering contains detailed information about the size and composition of particles. These volume scattering functions (VSFs) were measured in Mobile Bay, Alabama, USA, a dynamic, PIM dominated coastal environment. From measured VSFs, we determined through inversion the particle size distributions (PSDs) of major components of PIM, amorphous silica and clay minerals. An innovation here is the extension of our reported PSDs significantly into the sub-micron range. The PSDs of autochthonous amorphous silica exhibit two unique features: a peak centered at about 0.8mm between 0.2 and 4mm and a very broad shoulder essentially extending from 4mm to\u3e100mm. With an active and steady particle source from blooming diatoms, the shapes of amorphoussilica PSDs for sizes area, but showed more particles of sizes\u3e10mm inside the bay, likely due to wind-induced resuspension of larger frustules that have settled. Compared to autochthonous amorphous silica, the allochthonous clay minerals are denser and exhibit relatively narrower PSDs with peaks located between 1 and 4mm. Preferential settling of larger mineral particles as well as the smaller but denser illite component further narrowed the size distributions of clay minerals as they were being transported outside the bay. The derived PSDs also indicated a very dynamic situation in Mobile Bay when a cold weather front passed through during the experiment. With northerly winds of speeds up to 15 m s-1, both amorphous silica and clay minerals showed a dramatic increase in concentration and broadening in size distribution outside the exit of the barrier islands, indicative of wind-induced resuspension and subsequent advection of particles out of Mobile Bay. While collectively recognized as the PIM, amorphous silica and clay minerals, as shown in this study, possess very different size distributions. Considering how differences in PSDs and the associated particle areas will effect differences in sorption/desorption properties of these components, the results also demonstrate thepotential of applying VSF-inversion in studying biogeochemistry in the estuarine-coastal ocean system

From Meters to Kilometers: A Look at Ocean-Color Scales of Variability, Spatial Coherence, and the Need for Fine-Scale Remote Sensing in Coastal Ocean Optics

The physical, biological, chemical, and optical processes of the ocean operate on a wide variety of spatial and temporal scales, from seconds to decades and from micrometers to thousands of kilometers (Dickey et al., this issue; Dickey, 1991). These processes drive the accumulation and loss of living and nonliving mass constituents in the water column (e.g., nutrients, phytoplankton, detritus, sediments). These mass constituents frequently have unique optical characteristics that alter the clarity and color of the water column (e.g., Preisendorfer, 1976). This alteration of the ocean color, or more specifically the change in the spectral “water-leaving radiance,” L(λ), has led to the development of optical techniques to sample and study the change in biological and chemical constituents (Schofield et al., this issue). Thus, these optical techniques provide a mechanism to study the effects of underlying biogeochemical processes. In addition, because time- and space-dependent changes in L(λ) may be measured remotely, optical oceanography provides a way to sample ecological interactions over a wide range of spatial and temporal scales. The question often posed by scientists trying to resolve problems involving the temporal and spatial variation of oceanic properties is: “What is the optimal time/ space sampling frequency?” The obvious answer is that the sampling frequency should be one half the frequency of the variation (i.e., Nyquist frequency) of the property of interest. However, therein lies the rub for the oceanographer: the range of the relevant scales is large, and the range of available resources and/or actual engineering capabilities to sample all relevant scales is often small. Hence, the decisions affecting resource allocation become critical in order to maximize the total data information in both quantity and quality. While these scientific resource decisions are rarely discussed in explicit terms of cost-benefit analysis, such discussions should be integral parts of the scientific design of instruments, platforms, and experiments aimed at resolving oceanic processes. The practical examples of this problem in remote sensing include: “What is the optimal repeat coverage frequency?” and “What is the optimal Ground Sample Distance (GSD) or pixel size of the data?” For the optical oceanographer, there is also the issue of optimal spectral coverage needed to resolve the optical constituents of interest (Chang et al., this issue). The sum of these considerations feed into the sensor, deployment platform, and deployment schedule decisions. For polarorbiting and geo-stationary satellites that cost hundreds of millions of dollars, as well as airborne sensors that have smaller upfront costs but higher deployment costs, the decision of sampling frequency directly impacts the scientific use of the data stream, and what processes may be addressed with data streams collected by these sensors. These scientific cost-benefit analyses extend beyond the cost in dollars because the typical lifetime and replacement cycle of these sensors is on the order of years to decades, and a poorly designed sensor package is very difficult to replace. In 2001, the Office of Naval Research (ONR) sponsored the Hyperspectral Coastal Ocean Dynamics Experiment (HyCODE) (Dickey et al., this issue), which presented the opportunity to study the question of scales of variability in remote-sensing data. Hyperspectral airborne sensors were deployed on several platforms at various altitudes. This coverage was supplemented by numerous space-borne, remote-sensing satellites. The airborne instruments included two versions of the Portable Hyperspectral Imager for Low-Light Spectroscopy (PHILLS 1 and PHILLS 2) (Davis et al., 2002) operating at an altitude of less than 10,000 feet and 30,000 feet, respectively, as well as the NASA Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) sensor operating at 60,000 feet. These sensors provided hyperspectral data at 2 m, 9 m, and 20 m GSDs, respectively. The satellite data collected included the multi-spectral images from Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Moderate Resolution Imaging Spectroradiometer (MODIS), Fengyun 1 C (FY1-C), Oceansat as well as the multispectral polarimeter Multiangle Imaging SpectroRadiometer (MISR) sensor and sea surface temperature (SST) sensor Advanced Very High Resolution Radiometer (AVHRR). These collections provided a wealth of remote- sensing and field data during a spatially and temporally intense oceanographic field campaign, and they offered the ability to begin to address the issue of optimal sampling scales for the coastal ocean. The use of these multiple remote-sensing data streams requires the calibration, validation, and atmospheric correction of the sensor signals to retrieve estimates of L(λ), or “remote sensing reflectance,” Rᵣₛ(λ), a normalized measure of the L(λ). Our goals in this paper are to illuminate some of the issues of remote sensing spatial scaling in the nearshore environment and attempt to derive some understanding of appropriate sampling scales in the nearshore environment. We will focus on the data collected by a single sensor (PHILLS 2) to reduce uncertainties in the analysis that may result from the different data processing techniques applied to each of the individual sensors’ data

Video-tracking and On-plant Tests Show Cry1Ab Resistance Influences Behavior and Survival of Neonate Ostrinia nubilalis Following Exposure to Bt Maize

To examine how resistance to Bacillus thuringiensis (Bt) toxins influences movement and survival of European corn borer (Ostrinia nubilalis [Hübner]) neonates, the responses of Cry1Ab-resistant , -susceptible, and hybrid (F1) larvae were examined using two different techniques. First, using an automated video-tracking system, aspects of O. nubilalis movement were quantified in the presence of artificial diet incorporating 50% non-Bt or insect-resistant Cry1Ab maize tissue. Second, O. nubilalis dispersal and survival were measured 48–72 h after hatching on a Cry1Ab maize plant surrounded by two non-Bt maize plants. Video tracking indicated the presence of Cry1Ab tissue increased the total distance moved (m), time moving (%), and time away from the diet (%) for O. nubilalis while decreasing meander (degrees/cm). However, resistant larvae showed reduced movement and increased meander (≈localized searching) relative to susceptible or hybrid larvae on diet incorporating Cry1Ab tissue. Conversely, when placed onto Cry1Ab maize plants, resistant larvae were more likely than susceptible O. nubilalis to disperse onto adjacent non-Bt plants. The difference in on-plant dispersal seems to reflect greater survival after toxin exposure for resistant larvae rather than increased activity. These results suggest that simplified ‘Petri dish’ tests may not be predictive of larval movement among non-Bt and insect-resistant Bt maize plants. Because models of O. nubilalis resistance evolution incorporate various movement and survival parameters, improved data for on-plant behavior and survival of Bt- resistant , -susceptible, and hybrid larvae should help preserve the efficacy of transgenic insect-resistant maize

Juvenile Songbirds Compensate for Displacement to Oceanic Islands during Autumn Migration

To what degree juvenile migrant birds are able to correct for orientation errors or wind drift is still largely unknown. We studied the orientation of passerines on the Faroe Islands far off the normal migration routes of European migrants. The ability to compensate for displacement was tested in naturally occurring vagrants presumably displaced by wind and in birds experimentally displaced 1100 km from Denmark to the Faroes. The orientation was studied in orientation cages as well as in the free-flying birds after release by tracking departures using small radio transmitters. Both the naturally displaced and the experimentally displaced birds oriented in more easterly directions on the Faroes than was observed in Denmark prior to displacement. This pattern was even more pronounced in departure directions, perhaps because of wind influence. The clear directional compensation found even in experimentally displaced birds indicates that first-year birds can also possess the ability to correct for displacement in some circumstances, possibly involving either some primitive form of true navigation, or ‘sign posts’, but the cues used for this are highly speculative. We also found some indications of differences between species in the reaction to displacement. Such differences might be involved in the diversity of results reported in displacement studies so far

Atomic Resonance and Scattering

Contains reports on six research projects.National Science Foundation (PHY83-06273)Joint Services Electronics Program (DAAL03-86-K-0002)National Science Foundation (PHY84-11483)U.S. Navy-Office of Naval Research (Grant N00014-79-C-0183)Joint Services Electronics Program (Contract DAAG29-83-K-0003)National Science Foundation (Grant PHY83-07172-A01)U.S. Navy - Office of Naval Research (Grant N00014-83-K-0695)National Science Foundation (Grant CHE84-21392

Targeting HER2/neu with a fully human IgE to harness the allergic reaction against cancer cells

Breast and ovarian cancer are two of the leading causes of cancer deaths among women in the United States. Overexpression of the HER2/neu oncoprotein has been reported in patients affected with breast and ovarian cancers, and is associated with poor prognosis. To develop a novel targeted therapy for HER2/neu expressing tumors, we have constructed a fully human IgE with the variable regions of the scFv C6MH3-B1 specific for HER2/neu. This antibody was expressed in murine myeloma cells and was properly assembled and secreted. The Fc region of this antibody triggers in vitro degranulation of rat basophilic cells expressing human FcεRI (RBL SX-38) in the presence of murine mammary carcinoma cells that express human HER2/neu (D2F2/E2), but not the shed (soluble) antigen (ECDHER2) alone. This IgE is also capable of inducing passive cutaneous anaphylaxis in a human FcεRIα transgenic mouse model, in the presence of a cross-linking antibody, but not in the presence of soluble ECDHER2. Additionally, IgE enhances antigen presentation in human dendritic cells and facilitates cross-priming, suggesting that the antibody is able to stimulate a secondary T-cell anti-tumor response. Furthermore, we show that this IgE significantly prolongs survival of human FcεRIα transgenic mice bearing D2F2/E2 tumors. We also report that the anti-HER2/neu IgE is well tolerated in a preliminary study conducted in Macaca fascicularis (cynomolgus) monkeys. In summary, our results suggest that this IgE should be further explored as a potential therapeutic against HER2/neu overexpressing tumors, such as breast and ovarian cancers.Fil: Daniels, Tracy R.. University of California at Los Angeles; Estados UnidosFil: Leuchter, Richard K.. University of California at Los Angeles; Estados UnidosFil: Quintero, Rafaela. University of California; Estados UnidosFil: Helguera, Gustavo Fernando. University of California at Los Angeles; Estados Unidos. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodríguez, José A.. University of California at Los Angeles; Estados UnidosFil: Martínez Maza, Otoniel. University of California at Los Angeles; Estados UnidosFil: Schultes, Birgit C.. Advanced Immune Therapeutics, Inc.; Estados Unidos. Momenta Pharmaceuticals, Inc.; Estados UnidosFil: Nicodemus, Christopher F.. Advanced Immune Therapeutics, Inc.; Estados UnidosFil: Penichet, Manuel L.. University of California at Los Angeles; Estados Unido

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Parameters for the mathematical modelling of Clostridium difficile acquisition and transmission: a systematic review

INTRODUCTION: Mathematical modelling of Clostridium difficile infection dynamics could contribute to the optimisation of strategies for its prevention and control. The objective of this systematic review was to summarise the available literature specifically identifying the quantitative parameters required for a compartmental mathematical model of Clostridium difficile transmission. METHODS: Six electronic healthcare databases were searched and all screening, data extraction and study quality assessments were undertaken in duplicate. Results were synthesised using a narrative approach. RESULTS: Fifty-four studies met the inclusion criteria. Reproduction numbers for hospital based epidemics were described in two studies with a range from 0.55 to 7. Two studies provided consistent data on incubation periods. For 62% of cases, symptoms occurred in less than 4 weeks (3-28 days) after infection. Evidence on contact patterns was identified in four studies but with limited data reported for populating a mathematical model. Two studies, including one without clinically apparent donor-recipient pairs, provided information on serial intervals for household or ward contacts, showing transmission intervals of <1 week in ward based contacts compared to up to 2 months for household contacts. Eight studies reported recovery rates of between 75%-100% for patients who had been treated with either metronidazole or vancomycin. Forty-nine studies gave recurrence rates of between 3% and 49% but were limited by varying definitions of recurrence. No study was found which specifically reported force of infection or net reproduction numbers. CONCLUSIONS: There is currently scant literature overtly citing estimates of the parameters required to inform the quantitative modelling of Clostridium difficile transmission. Further high quality studies to investigate transmission parameters are required, including through review of published epidemiological studies where these quantitative estimates may not have been explicitly estimated, but that nonetheless contain the relevant data to allow their calculation