340 research outputs found
Modular Autonomous Biosampler (MAB)- A prototype system for distinct biological size-class sampling and preservation
Presently, there is a community wide deficiency in our ability to collect and preserve multiple size-class biologic samples across a broad spectrum of oceanographic platforms (e.g. AUVs, ROVs, and Ocean Observing System Nodes). This is particularly surprising in comparison to the level of instrumentation that now exists for acquiring physical and geophysical data (e.g. side-scan sonar, current profiles etc.), from these same platforms. We present our effort to develop a low-cost, high sample capacity modular,autonomous biological sampling device (MAB). The unit is designed for filtering and preserving 3 distinct biological size-classes (including bacteria), and is deployable in any aquatic setting from a variety of platform modalities (AUV, ROV, or mooring)
Has climate change taken prominence over biodiversity conservation?
The growing prominence of climate change has led to concerns that other important environmental issues, such as biodiversity loss, are being overshadowed. We investigate this assertion by examining trends in biodiversity and climate change coverage within the scientific and newspaper press, as well as the relative distribution of funding through the World Bank and the National Science Foundation, since the late 1980s. Our indicators substantiate some of these fears. To prevent biodiversity from becoming a declining priority, conservationists need to analyze the discourse surrounding climate change and determine how it has become the predominant environmental topic. In addition, given the common drivers of biodiversity loss and climate change, we argue that win–win solutions must be sought wherever possible. Conservationists need to be proactive and take this opportunity to use the mounting interest in climate change as a flagship to leverage more support and action to prevent further biodiversity loss
Historical data as a baseline for conservation: reconstructing long-term faunal extinction dynamics in Late Imperial–modern China
Extinction events typically represent extended processes of decline that cannot be reconstructed using short-term studies. Long-term archives are necessary to determine past baselines and the extent of human-caused biodiversity change, but the capacity of historical datasets to provide predictive power for conservation must be assessed within a robust analytical framework. Local Chinese gazetteers represent a >400-year country-level dataset containing abundant information on past environmental conditions and include extensive records of gibbons, which have a restricted present-day distribution but formerly occurred across much of China. Gibbons show pre-twentieth century range contraction, with significant fragmentation by the mid-eighteenth century and population loss escalating in the late nineteenth century. Isolated gibbon populations persisted for ~40 years before local extinction. Populations persisted for longer at higher elevations, and disappeared earlier from northern and eastern regions, with the biogeography of population loss consistent with the contagion model of range collapse in response to human demographic expansion spreading directionally across China. The long-term Chinese historical record can track extinction events and human interactions with the environment across much longer timescales than are usually addressed in ecology, contributing novel baselines for conservation and an increased understanding of extinction dynamics and species vulnerability or resilience to human pressures
Manoeuvring Experiments Using the MUN Explorer AUV
Autonomous Underwater Vehicles (AUVs) are
self-propelled robotic platforms that can perform a
predetermined mission completely unmanned. A series of
manoeuvring experiments were performed using the MUN
Explorer AUV during the summer of 2006 and a selection of
these experimental results are presented in this paper. The
purpose of these experiments was to collect a set of useful
data for validating a hydrodynamic model of the dynamic
performance of the vehicle. This paper aims at explaining the
methods and measures adopted in accomplishing this task.
Apart from providing a data set for validation of the
hydrodynamic model, the data record also shows the ability
of the AUV to perform extreme manoeuvres and the accuracy
with which it can follow a pre-planned mission
Manoeuvring Trials with the MUN Explorer AUV: Data Analysis and Observations
Manoeuvring trials are usually performed to
determine the manoeuvring characteristics of a marine vehicle. It
is through certain standard manoeuvres we evaluate the
robustness, performance and limitations of the vehicle control
system. A series of open-water manoeuvring trials were
performed using the MUN Explorer AUV in the summer of 2006.
The actual purpose of these experiments was to collect a set of
experimental data in order to validate a hydrodynamic model of
the dynamic performance of the vehicle. This paper presents the
results and observations from the analysis of a set of
manoeuvring trials data: in particular the results from straightline
(acceleration – deceleration) tests and turning circles. It
outlines briefly the method by which these tests were conducted
and discusses the results and observations made. Apart from
providing a data set for validation purposes, the results also
indicate the ability of the vehicle to follow a pre-planned mission
with precision
Moth Diversity of the Grand River Grasslands of South-central Iowa
Moths play important roles in local ecosystems and many species have important economic impacts. Moths are some of the most diverse organisms on Earth, composing about 10% of all known species. Eastern North America alone is home to thousands of species. Though they are incredibly diverse, and have large economic impacts, there is still little knowledge regarding the geographic distribution or population size for most of these species. Iowa is one of most diverse states for moths as it is situated between several broad areas with regionally endemic species including: the North, the Northeast, the Plains, and the annual migration of species from the South. In this study lights were used to attract specimens that were photographed and released. Over two seasons, 316 species were encountered from six different locations in Ringgold and Decatur counties. Several species encountered in this research project represent species that had previously never been observed in Iowa
Hind Wing Eyespots of Brassolini Butterflies (Lepidoptera, Nymphalidae): Evolutionary Diversification and Functions in Anti-predator Defense and Mating Behavior
Ventral hind wing eyespots are prominent pattern elements in Brassolini butterflies, likely functioning in predator-prey interactions and reproductive activities. Caligo and Opsiphanes differ in male mate-seeking behaviors and it has been suggested that Caligo females use the male cua1 eyespot as a mate-locating cue, but Opsiphanes females do not seem to do so. We predict Caligo males should have larger eyespots than congeneric females, but the sexes would not differ in eyespot size in Opsiphanes. Our analyses supported both these predictions. Displacing the eyespot to the center of the wing makes eyespots more conspicuous, we asked if eyespot position and size covaried across the Brassolini phylogeny. While we did observe a positive relationship, we found these two variables contained significant phylogenetic signal. Our study suggests that the cua1 eyespot performs multiple functions in Brassolini and might be evolving under natural and sexual selection
Synthesis and coordination chemistry of 2-(di-2-pyridylamino)pyrimidine; structural aspects of spin crossover in an Fe(II) complex
This paper was accepted on February 26 20122-(Di-2-pyridylamino)pyrimidine (L), a potentially ditopic tetradentate ligand, was synthesized from commercially available di-2-pyridylamine and 2-chloropyrimidine. Despite being capable of bridging two metal atoms with bidentate chelation of both metal centres, L prefers to chelate or bridge through the more basic pyridyl donors of the di-2-pyridylamine moiety. Mononuclear trans-[Fe(NCS)2(L)2] and [Cu(L)2(H2O)](BF4)2•H2O complexes, and a discrete [Ag2(L)4](PF6)2 metallomacrocycle were isolated and structurally characterized by X-ray crystallography. A mononuclear palladium complex [PdCl2(L)]•(solvate), where solvate = ½H2O or CH2Cl2, was also readily obtained in 71% yield. One example of the ligand acting as a bis(bidentate) bridging ligand was observed in a dinuclear [(PdCl2)2(L)]•¾H2O complex that was obtained only in very low yield (ca. 3%) from the reaction that produced [PdCl2(L)]•½H2O. trans-[Fe(NCS)2(L)2] undergoes a temperature dependent HS-LS (HS = high spin; LS = low spin) crossover at ca. 205 K that was 2 observed by X-ray crystallography and magnetic measurements and attempts were made to understand the structural basis of this process. Despite efforts to isolate examples of L bridging two iron(II) centres, only the mononuclear trans-[Fe(NCS)2(L)2] species could be obtained.Rachel S. Crees, Boujemma Moubaraki, Keith S. Murray, and Christopher J. Sumb
Cellular therapy updates in B-cell lymphoma: The state of the CAR-T
Non-Hodgkin Lymphoma accounts for \u3e460,000 cases and \u3e240,000 deaths globally and \u3e77,000 cases and \u3e20,000 deaths in the U.S. annually, with ~85% of cases being B-cell malignancies. Until recently, patients with relapsed/refractory B-cell lymphoma following standard chemotherapy in combination with anti-CD20 monoclonal antibodies and autologous stem cell transplantation experienced a median overall survival (OS) of \u3c6 months. However, with the approval of four different CD-19 CAR-T therapies between 2017 and 2021, approximately 60-80% of patients receiving CAR-T therapy now achieve an objective response with \u3e3 years median OS. Here, we review the current state of the art of CD19 CAR-T therapies for B-cell lymphomas, focusing on current updates in US FDA-approved products, along with their associated efficacy and toxicities. Lastly, we highlight a selection of promising clinical developments in the field, including various novel strategies to increase CAR-T therapy efficacy while mitigating toxicity
Post-Secular Thought? God, No! Slavoj Zizek, the Lacanian Real and the Swerve of Symbolic Space
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