138 research outputs found
The Effect of Alien Predatory Ants (Hymenoptera: Formicidae) on Hawaiian Endemic Spiders (Araneae: Tetragnathidae)
The fauna of the Hawaiian Islands is characterized by spectacular
species radiations with high levels of endemism, which is coupled with an extreme
vulnerability to invasion by alien species. Of all alien invertebrate predators, ants
are most notorious in their effect on native Hawaiian biota. This study examined
distribution of ants in mesic and wet forests throughout the Hawaiian Islands
and the extent to which they overlap the range of representatives of a lineage
of endemic Hawaiian invertebrates, the genus Tetragnatha (Araneae: Tetragnathidae).
Two species, Pheidole megacephala (F.) and Anoplolepis longipes
(Jerdon), were implicated in the exclusion of native spiders from native and
disturbed forest. One species, Solenopsis papuana Emery, showed extensive
overlap in its range with that of the native spiders. However, we found a
significant inverse relationship between the abundance of S. papuana in an area
and the diversity of the indigenous Tetragnatha. Interactions between the spiders
and the two species of ants, P. megacephala and A. longipes, were conducted in
the laboratory and indicated that the spiders were very vulnerable to attack by
these ants. Alien spiders appear to tolerate the presence of ants because they
have either a strong exoskeleton, can appendotomize their legs, or else are
capable of wrapping the ant in silk. Spiders that normally coexist with ants
appear to use one or more of these methods for defense. The riparian existence
of the genus Tetragnatha outside Hawaii may protect it from predation by ants.
In Hawaii, where their habitat preference is no longer restricted to riparian sites,
they may be extremely vulnerable to these alien predators
Red Imported Fire Ant, a Seriously Harmful Potential Invasive Species
Although Solenopsis invicta is not present in Hawaii, this publication advised of the threat its possible introduction poses; its biology and potential impacts are described. The distinction between this pest and S. geminata, the tropical fire ant, which is present in Hawaii, is described
Bait Preference by the Argentine Ant (Hymenoptera: Formicidae) In Haleakala National Park, Hawaii
The Argentine ant, Linepithema humile (Mayr), has proven to be a threat to native arthropod species in Haleakala National Park, Maui, HI, and is also a potential threat to the park\u27s native flora. As it continues to expand its range, an effort has been undertaken to eradicate it, or at the least, control its spread. The 1st part of this effort focused on finding a bait carrier for subsequent toxicant-based control tests. A year-long bait preference test was implemented at each of the ant\u27s 2 infestation sites in Haleakala National Park, in which 6 solid baits and 2 liquid baits were assessed for attractiveness and feasibility for large scale control. At both sites, a toxicant-free formulation of Maxforce, a protein-based granular bait made from ground silkworm, Bombyx mori (L.), pupae, and a 25% sugar water solution were the most attractive baits. Ants took more Maxforce (without toxicant) and sugar water than all other baits, including honey granules and a fish protein bait. Sugar water, however, is difficult to distribute over large natural areas. Maxforce was therefore concluded to be the best bait carrier for toxicant-based control at Haleakala National Park because of its attractiveness and its ease for large scale broadcast dispersal
A lack of freshwater reservoir effects in human radiocarbon dates in the Eneolithic to Iron Age in the Minusinsk Basin
A number of recent studies have highlighted the importance
of freshwater reservoir effects (FRE) when dating human
remains across large parts of Eurasia, including the Eurasian
steppes. Here,we address this question in the context of the Early
Bronze Age (Okunevo), Late Bronze Age (Karasuk) and Late
Iron Age (Tashtyk culture) of the Minusinsk Basin, Southern
Siberia. The issue is important given the large number of radiocarbon
dates that have been published on human remains here,
which have been used both to refine the cultural historical sequence
(Svyatko et al. 2009), as well as to suggest a date of ca.
1400 BC for the appearance of millet agriculture (Svyatko et al.
2013). In these studies, it was argued that there was little or no
freshwater reservoir effect to take into account, despite the likely
consumption of freshwater fish. Subsequent work across the
steppe raised a legitimate question concerning this assumption.
Here, we present the first set of paired dates on late prehistoric
humans and terrestrial fauna from the Minusinsk Basin, as well
as data from modern fish for the region. The results, with one
exception, show no clear evidence for a reservoir effect, with the
human-fauna difference averaging −31 ± 95 14C years. Yet,
dating of modern fish from the Yenisei River and its tributary
Karasuk River does show a variable but significant FRE. Either
this effect has changed radically over time, or the contribution of
fish to human diets in the Minusinsk Basin was less than previously
thought
Design and introduction of a quality of life assessment and practice support system: perspectives from palliative care settings
Background:
Quality of life (QOL) assessment instruments, including patient-reported outcome measures (PROMs) and patient-reported experience measures (PREMs), are increasingly promoted as a means of enabling clinicians to enhance person-centered care. However, integration of these instruments into palliative care clinical practice has been inconsistent. This study focused on the design of an electronic Quality of Life and Practice Support System (QPSS) prototype and its initial use in palliative inpatient and home care settings. Our objectives were to ascertain desired features of a QPSS prototype and the experiences of clinicians, patients, and family caregivers in regard to the initial introduction of a QPSS in palliative care, interpreting them in context.
Methods:
We applied an integrated knowledge translation approach in two stages by engaging a total of 71 clinicians, 18 patients, and 17 family caregivers in palliative inpatient and home care settings. Data for Stage I were collected via 12 focus groups with clinicians to ascertain desirable features of a QPSS. Stage II involved 5 focus groups and 24 interviews with clinicians and 35 interviews with patients or family caregivers during initial implementation of a QPSS. The focus groups and interviews were recorded, transcribed, and analyzed using the qualitative methodology of interpretive description.
Results:
Desirable features focused on hardware (lightweight, durable, and easy to disinfect), software (simple, user-friendly interface, multi-linguistic, integration with e-health systems), and choice of assessment instruments that would facilitate a holistic assessment. Although patient and family caregiver participants were predominantly enthusiastic, clinicians expressed a mixture of enthusiasm, receptivity, and concern regarding the use of a QPSS. The analyses revealed important contextual considerations, including: (a) logistical, technical, and aesthetic considerations regarding the QPSS as a technology, (b) diversity in knowledge, skills, and attitudes of clinicians, patients, and family caregivers regarding the integration of electronic QOL assessments in care, and (c) the need to understand organizational context and priorities in using QOL assessment data.
Conclusion:
The process of designing and integrating a QPSS in palliative care for patients with life-limiting conditions and their family caregivers is complex and requires extensive consultation with clinicians, administrators, patients, and family caregivers to inform successful implementation
Low-repetition-rate Integrated Electro-optic Frequency Comb Sources
We demonstrate a low-repetition-rate lithium niobate based electro-optic (EO) frequency comb operating with 3.481 GHz line spacing, by integrating a cavity-based EO comb source with traveling-wave phase-modulators on the same chip
Magnetic field induced delocalization in hybrid electron-nuclear spin ensembles
We use field-cycling-assisted dynamic nuclear polarization and continuous radio-frequency (RF) driving over a broad spectral range to demonstrate magnetic-field-dependent activation of nuclear spin transport from strongly hyperfine-coupled C13 sites in diamond. We interpret our observations with the help of a theoretical framework where nuclear spin interactions are mediated by electron spins. In particular, we build on the results from a four-spin toy model to show how otherwise localized nuclear spins must thermalize as they are brought in contact with a larger ancilla spin network. Further, by probing the system response to a variable driving field amplitude, we witness stark changes in the RF-absorption spectrum, which we interpret as partly due to contributions from heterogeneous multispin sets, whose zero-quantum transitions become RF active thanks to the hybrid electron-nuclear nature of the system. These findings could prove relevant in applications to dynamic nuclear polarization, spin-based quantum information processing, and nanoscale sensing.Fil: Pagliero, Daniela. City University Of New York. The Graduate Center; Estados UnidosFil: Zangara, Pablo René. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Henshaw, Jacob. City University of New York. The City College of New York; Estados UnidosFil: Ajoy, Ashok. University of California at Berkeley; Estados UnidosFil: Acosta, Rodolfo Héctor. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Manson, Neil. Australian National University; AustraliaFil: Reimer, Jeffrey A.. University of California at Berkeley; Estados Unidos. Lawrence Berkeley National Laboratory; Estados UnidosFil: Pines, Alexander. University of California at Berkeley; Estados Unidos. Lawrence Berkeley National Laboratory; Estados UnidosFil: Meriles, Carlos A.. City University Of New York. The Graduate Center; Estados Unido
Magnetic-field-induced delocalization in hybrid electron-nuclear spin ensembles
We use field-cycling-assisted dynamic nuclear polarization and continuous
radio-frequency (RF) driving over a broad spectral range to demonstrate
magnetic-field-dependent activation of nuclear spin transport from
strongly-hyperfine-coupled 13C sites in diamond. We interpret our observations
with the help of a theoretical framework where nuclear spin interactions are
mediated by electron spins. In particular, we build on the results from a
4-spin toy model to show how otherwise localized nuclear spins must thermalize
as they are brought in contact with a larger ancilla spin network. Further, by
probing the system response to a variable driving field amplitude, we witness
stark changes in the RF-absorption spectrum, which we interpret as partly due
to contributions from heterogeneous multi-spin sets, whose 'zero-quantum'
transitions become RF active thanks to the hybrid electron-nuclear nature of
the system. These findings could prove relevant in applications to dynamic
nuclear polarization, spin-based quantum information processing, and nanoscale
sensing
Spectral control of nonclassical light using an integrated thin-film lithium niobate modulator
Manipulating the frequency and bandwidth of nonclassical light is essential
for implementing frequency-encoded/multiplexed quantum computation,
communication, and networking protocols, and for bridging spectral mismatch
among various quantum systems. However, quantum spectral control requires a
strong nonlinearity mediated by light, microwave, or acoustics, which is
challenging to realize with high efficiency, low noise, and on an integrated
chip. Here, we demonstrate both frequency shifting and bandwidth compression of
nonclassical light using an integrated thin-film lithium niobate (TFLN) phase
modulator. We achieve record-high electro-optic frequency shearing of telecom
single photons over terahertz range ( 641 GHz or 5.2 nm), enabling
high visibility quantum interference between frequency-nondegenerate photon
pairs. We further operate the modulator as a time lens and demonstrate over
eighteen-fold (6.55 nm to 0.35 nm) bandwidth compression of single photons. Our
results showcase the viability and promise of on-chip quantum spectral control
for scalable photonic quantum information processing
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