6,216 research outputs found
Sublethal Behavioral and Physiological Effects of the Biomedical Bleeding Process on the American Horseshoe Crab, Limulus polyphemus
The hemolymph of the American horseshoe crab, Limulus polyphemus, is harvested from over 500,000 animals annually to produce Limulus amebocyte lysate (LAL), a medically important product used to detect pathogenic bacteria. Declining abundance of spawning Limulus females in heavily harvested regions suggests deleterious effects of this activity, and while mortality rates of the harvest process are known to be 10%–30%, sublethal behavioral and physiological effects are not known. In this study, we determined the impact of the harvest process on locomotion and hemocyanin levels of 28 female horseshoe crabs. While mortality rates after bleeding (18%) were similar to previous studies, we found significant decreases in the linear and angular velocity of freely moving animals, as well as changes in their activity levels and expression of circatidal behavioral rhythms. Further, we found reductions in hemocyanin levels, which may alter immune function and cuticle integrity. These previously unrecognized behavioral and physiological deficits suggest that the harvest of LAL may decrease female fitness, and thus may contribute to the current population decline
Millimeter and Submillimeter Survey of the R Corona Australis Region
Using a combination of data from the Antarctic Submillimeter Telescope and
Remote Observatory (AST/RO), the Arizona Radio Observatory Kitt Peak 12m
telescope and the Arizona Radio Observatory 10m Heinrich Hertz Telescope, we
have studied the most active part of the R CrA molecular cloud in multiple
transitions of Carbon Monoxide, HCO and 870\micron continuum emission.
Since R CrA is nearby (130 pc), we are able to obtain physical spatial
resolution as high as 0.01pc over an area of 0.16 pc, with velocity
resolution finer than 1 km/s. Mass estimates of the protostar driving the
mm-wave emission derived from HCO, dust continuum emission and kinematic
techniques point to a young, deeply embedded protostar of 0.5-0.75
M, with a gaseous envelope of similar mass. A molecular outflow is
driven by this source that also contains at least 0.8 M of molecular
gas with 0.5 L of mechanical luminosity. HCO lines show the
kinematic signature of infall motions as well as bulk rotation. The source is
most likely a Class 0 protostellar object not yet visible at near-IR
wavelengths. With the combination of spatial and spectral resolution in our
data set, we are able to disentangle the effects of infall, rotation and
outflow towards this young object.Comment: 29 pages, 9 figures. Accepted for publication in the Astrophysical
Journa
Progress on Fishery Performance Indicators (FPIs)
This is the supplemental PowerPoint for the presentation given at the IIFET Conference in Dar es Salaam, Tanzania. Provides bulleted points regarding the progress, lessons learned, policy recommendations based on Fishery Performance Indicators under evaluation in both developed and developing countries
High-resolution antenna near-field imaging and sub-THz measurements with a small atomic vapor-cell sensing element
Atomic sensing and measurement of millimeter-wave (mmW) and THz electric
fields using quantum-optical EIT spectroscopy of Rydberg states in atomic
vapors has garnered significant interest in recent years towards the
development of atomic electric-field standards and sensor technologies. Here we
describe recent work employing small atomic vapor cell sensing elements for
near-field imaging of the radiation pattern of a K-band horn antenna at
13.49 GHz. We image fields at a spatial resolution of and measure
over a 72 to 240 V/m field range using off-resonance AC-Stark shifts of a
Rydberg resonance. The same atomic sensing element is used to measure sub-THz
electric fields at 255 GHz, an increase in mmW-frequency by more than one order
of magnitude. The sub-THz field is measured over a continuous 100 MHz
frequency band using a near-resonant mmW atomic transition
Electronic Tuning of Mixed Quinoidal‐Aromatic Conjugated Polyelectrolytes: Direct Ionic Substitution on Polymer Main‐Chains
The synthesis of conjugated polymers with ionic substituents directly bound to their main chain repeat units is a strategy for generating strongly electron-accepting conjugated polyelectrolytes, as demonstrated through the synthesis of a series of ionic azaquinodimethane (iAQM) compounds. The introduction of cationic substituents onto the quinoidal para-azaquinodimethane (AQM) core gives rise to a strongly electron-accepting building block, which can be employed in the synthesis of ionic small molecules and conjugated polyelectrolytes (CPEs). Electrochemical measurements alongside theoretical calculations indicate notably low-lying LUMO values for the iAQMs. The optical band gaps measured for these compounds are highly tunable based on structure, ranging from 2.30 eV in small molecules down to 1.22 eV in polymers. The iAQM small molecules and CPEs showcase the band gap reduction effects of combining the donor-acceptor strategy with the bond-length alternation reduction strategy. As a demonstration of their utility, the iAQM CPEs so generated were used as active agents in photothermal therapy
Custom astrocyte-mediated vasomotor responses to neuronal energy demand
Brain astrocytes regulate local blood flow and neuronal energy supply by modulating blood vessel tone in response to changes in oxygen levels
KOMPARASI HASIL BELAJAR SISWA MENGGUNAKAN MODEL PEMBELAJARAN KOOPERATIF TIPE STUDENT FACILITATOR AND EXPLAINING DAN TIPE THINK PAIR SHARE
This study aims to determine the comparison of student learning outcomes using the Student Facilitator and Explaining (SFE) Cooperative Learning Model and the Think Pair Share (TPS) Cooperative Learning Model on quadrilateral material in grade VII Christian Middle School Kusu-Kusu Sereh Ambon. The type of research used is experimental research (Experimental Research) with a Post Test Group Design research design. In this study, the population used was all students of class VII Kusu-Kusu Christian Middle School, Sereh Ambon, which consisted of 2 classes with a total of 40 students, selected using the Total Sampling technique. The instrument used in the study was in the form of test questions consisting of 5 description questions for the final test. The study made experimental class students one and experimental class two students using the Student Facilitator and Explaining (SFE) Cooperative Learning Model and Think Pair Share (TPS) Cooperative Learning Model on rectangular material. Based on the statistical analysis of the t-test, the value of Sig.(2-tailed) 0.124 is greater than = 0.05, so there is no significant difference between the two models. Furthermore, the Mean value in the Group Statistics table shows that the Mean value of Student Facilitator and Explaining is 65.92 and the Mean value of Think Pair Share is 57.77. These results can be proven that the superior learning model is the Student Facilitator and Explaining (SFE) Cooperative Learning Mode
- …