295 research outputs found
A review of Malta’s pre-temple Neolithic pottery wares
Sites from the earliest known phases of Maltese prehistory often consist of scatters of sherds for the
Għar Dalam and Skorba phases (6000–4800 BCE), and tomb contexts for the Żebbuġ phase (3800–3600 BCE).
Neolithic studies are, therefore, heavily reliant on the study of pottery. Although traditional typological and
seriation-based analyses of the pottery record have substantially enhanced our knowledge of Early Neolithic
Malta, there is a growing appreciation of the need to go beyond these approaches to gain new insights. This
study reviews the accessible literature on fabric studies on assemblages found in the Maltese Islands, presenting
the state of knowledge for the pottery of the Għar Dalam, Skorba (Early Neolithic), and Żebbuġ (Late
Neolithic) phases. Microphotographs of pottery wares were selected from a compilation produced for an
ongoing project (the MaltaPot project) to illustrate the descriptions found in the literature. The advances
made by archaeologists in studying the Maltese Neolithic pottery are reviewed, and suggestions for building
on them are proposed, as archaeometric and petrographic techniques have not been applied systematically to
Neolithic pottery from Malta.peer-reviewe
The error of our ways: the experience of self-reported position in a location-based game
We present a study of people’s use of positional information as part
of a collaborative location-based game. The game exploits self-reported positioning
in which mobile players manually reveal their positions to remote players
by manipulating electronic maps. Analysis of players’ movements, position
reports and communications, drawing on video data, system logs and player
feedback, highlights some of the ways in which humans generate, communicate
and interpret position reports. It appears that remote participants are largely untroubled
by the relatively high positional error associated with self reports. Our
analysis suggests that this may because mobile players declare themselves to be
in plausible locations such as at common landmarks, ahead of themselves on
their current trajectory (stating their intent) or behind themselves (confirming
previously visited locations). These observations raise new requirements for the
future development of automated positioning systems and also suggest that selfreported
positioning may be a useful fallback when automated systems are unavailable
or too unreliable
Rural Malta : first results of the joint Belgo-Maltese survey project
The paper presents the first interdisciplinary results of a joint survey project in the north-west of Malta, with finds ranging from the Prehistoric till the Early Modern period. Three permanently inhabited sites were encountered dating to at least the late 6th or early 5th century BCE, with a clearer attestation in the Hellenistic/Roman and Late Antique periods. The resulting reconstructed settlement pattern of the Phoenician/Punic period suggests a managed landscape that seems to be a good reflexion of what is happening in North Africa and elsewhere in the central and western Mediterranean. At least from the Roman period on, these sites seem to have specialised on the production of olive oil.peer-reviewe
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
EMA-amplicon-based sequencing informs risk assessment analysis of water treatment systems
Illumina amplicon-based sequencing was coupled with ethidium monoazide bromide (EMA) pre-treatment to monitor the total viable bacterial community and subsequently identify and prioritise the target organisms for the health risk assessment of the untreated rainwater and rainwater treated using large-volume batch solar reactor prototypes installed in an informal settlement and rural farming community. Taxonomic assignments indicated that Legionella and Pseudomonas were the most frequently detected genera containing opportunistic bacterial pathogens in the untreated and treated rainwater at both sites. Additionally, Mycobacterium, Clostridium sensu stricto and Escherichia/Shigella displayed high (≥80%) detection frequencies in the untreated and/or treated rainwater samples at one or both sites. Numerous exposure scenarios (e.g. drinking, cleaning) were subsequently investigated and the health risk of using untreated and solar reactor treated rainwater in developing countries was quantified based on the presence of L. pneumophila, P. aeruginosa and E. coli. The solar reactor prototypes were able to reduce the health risk associated with E. coli and P. aeruginosa to below the 1 × 10−4 annual benchmark limit for all the non-potable uses of rainwater within the target communities (exception of showering for E. coli). However, the risk associated with intentional drinking of untreated or treated rainwater exceeded the benchmark limit (E. coli and P. aeruginosa). Additionally, while the solar reactor treatment reduced the risk associated with garden hosing and showering based on the presence of L. pneumophila, the risk estimates for both activities still exceeded the annual benchmark limit. The large-volume batch solar reactor prototypes were thus able to reduce the risk posed by the target bacteria for non-potable activities rainwater is commonly used for in water scarce regions of sub-Saharan Africa. This study highlights the need to assess water treatment systems in field trials using QMRA
Measuring the Intrapersonal Component of Psychological Empowerment: Confirmatory Factor Analysis of the Sociopolitical Control Scale
The Sociopolitical Control Scale (SPCS) is a widely used measure of the intrapersonal component of psychological empowerment. Confirmatory factor analyses (CFA) were conducted with data from two samples to test the hypothesized structure of the SPCS, the potential effects of method bias on the measure's psychometric properties, and whether a revised version of the scale (SPCS‐R) yielded improved model fit. Sample 1 included 316 randomly selected community residents of the Midwestern United States. Sample 2 included 750 community residents of the Northeastern U.S. Results indicated that method bias from the use of negatively worded items had a significant effect on the factor structure of the SPCS. CFA of the SPCS‐R, in which negatively worded items were rephrased so that all statements were positively worded, supported the measure's hypothesized two‐factor structure (i.e., leadership competence and policy control). Subscales of the SPCS‐R were found reliable and related in expected ways with measures of community involvement. Implications of the study for empowerment‐based research and practice are described, and strategies to further develop the SPCS are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117223/1/ajcp9070.pd
Instructive role of MLL-fusion proteins revealed by a model of t(4;11) pro-B acute lymphoblastic leukemia
Notch and Presenilin Regulate Cellular Expansion and Cytokine Secretion but Cannot Instruct Th1/Th2 Fate Acquisition
Recent reports suggested that Delta1, 4 and Jagged1, 2 possessed the ability to instruct CD4+ T cell into selection of Th1 or Th2 fates, respectively, although the underlying mechanism endowing the cleaved Notch receptor with memory of ligand involved in its activation remains elusive. To examine this, we prepared artificial antigen-presenting cells expressing either DLL1 or Jag1. Although both ligands were efficient in inducing Notch2 cleavage and activation in CD4+ T or reporter cells, the presence of Lunatic Fringe in CD4+ T cells inhibited Jag1 activation of Notch1 receptor. Neither ligand could induce Th1 or Th2 fate choice independently of cytokines or redirect cytokine-driven Th1 or Th2 development. Instead, we find that Notch ligands only augment cytokine production during T cell differentiation in the presence of polarizing IL-12 and IL-4. Moreover, the differentiation choices of naïve CD4+ T cells lacking γ-secretase, RBP-J, or both in response to polarizing cytokines revealed that neither presenilin proteins nor RBP-J were required for cytokine-induced Th1/Th2 fate selection. However, presenilins facilitate cellular proliferation and cytokine secretion in an RBP-J (and thus, Notch) independent manner. The controversies surrounding the role of Notch and presenilins in Th1/Th2 polarization may reflect their role as genetic modifiers of T-helper cells differentiation
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