1,046 research outputs found
A robust single input adaptive sliding mode fuzzy logic controller for a nonlinear active suspension system
Forward modelling of brightness variations in Sun-like stars I. Emergence and surface transport of magnetic flux
The latitudinal distribution of starspots deviates from the solar pattern
with increasing rotation rate. Numerical simulations of magnetic flux emergence
and transport can help model the observed stellar activity patterns and the
associated brightness variations. We set up a composite model for the processes
of flux emergence and transport on Sun-like stars, to simulate stellar
brightness variations for various levels of magnetic activity and rotation
rates. Assuming that the distribution of magnetic flux at the base of the
convection zone follows solar scaling relations, we calculate the emergence
latitudes and tilt angles of bipolar regions at the surface for various
rotation rates, using thin-flux-tube simulations. Taking these two quantities
as input to a surface flux transport SFT model, we simulate the
diffusive-advective evolution of the radial field at the stellar surface,
including effects of active region nesting. As the rotation rate increases, (1)
magnetic flux emerges at higher latitudes and an inactive gap opens around the
equator, reaching a half-width of for , (2) the tilt
angles of freshly emerged bipolar regions show stronger variations with
latitude. Polar spots can form at by accumulation of
follower-polarity flux from decaying bipolar regions. From to
, the maximum spot coverage changes from 3 to 20%, respectively,
compared to 0.4% for the solar model. Nesting of activity can lead to strongly
non-axisymmetric spot distributions. On Sun-like stars rotating at
( days), polar spots can form, owing to
higher levels of flux emergence rate and tilt angles. Defining spots by a
threshold field strength yields global spot coverages that are roughly
consistent with stellar observations.Comment: 16 pages, 13 figures. Astron. & Astrophys. (in press); minor language
corrections mad
A taxonomic review of the species of the genus Amara Bonelli (Coleoptera: Carabidae: Pterostichinae) from south-central Turkey
The twelve species and subspecies of the pterostichine genus Amara Bonelli living in the study area represent about 22% of the Turkish species of this genus. This study is based on material collected primarily in the province of Kahramanmara, but also in the surrounding provinces of Adana,Adýyaman, Gaziantep, Kayseri, and Malatya, situated in south-central Turkey, in the Taurus Mountains, and mostly within the Taurus refugium. The taxa are characterized by: keys; description of structural features; and photographs of habitus (male and female), and of male genitalia. For each species, thelocalities (many of them new), coordinates, altitudes of collection, its distribution in Turkey, and its chorotype were also given
The Role of Leucoyte-Derived Free Oxygen Radicals in the Pathogenesis of Experimental Acute Pancreatitis
The role of free oxygen radicals in experimental acute pancreatitis induced by common bile duct
ligation was investigated by measuring malondialdehyde levels in the rat pancreas. Also, the
potential role of leucocytes as the source of free oxygen radicals was tested by inducing
leukopenia with methotrexate. The malondialdehyde levels in the control, pancreatitis and
pancreatitis + methotrexate groups were 9.6 ± 2.0, 44.8 ± 11.4, and 25.6 ± 5.0 nmol malondialdehyde/
g pancreas tissue respectively. The corresponding histopathological severity scores were
0.5 ± 0.7, 8.1 ± 1.2 and 3.7 ± 1.1. The results suggest that the leucocyte may be an important
source of free oxygen radicals in this experimental model
Dull versus creative liars—Who deceives better? Fantasy proneness and verifiability of genuine and fabricated accounts
CYCLIC SEDIMENTATION ACROSS THE PERMIAN – TRIASSIC BOUNDARY (CENTRAL TAURIDES, TURKEY)
The best preserved Permian-Triassic boundary beds in Turkey are found in the Hadim region of the central Taurides. The succession is exposed in one of the allochthonous units of the Tauride Belt, the Aladag Unit, whose stratigraphy includes beds ranging from the Devonian to the Cretaceous systems. In the Aladag Unit, the Permian-Triassic boundary beds are entirely composed of carbonates. The Permian portion of these beds belongs to the Paradagmarita Zone, whereas the lowermost Triassic contains the Lower Griesbachian marker Rectocornuspira kalhori. The uppermost Permian carbonates, composed of meter-scale upward shallowing subtidal cycles, are characterized by oolitic limestones of regressive character at the top and are overlain sharply by Lower Triassic stromatolites. Cyclic Upper Permian carbonates are interpreted as highstand sytems tract deposits of the last third-order sequence of the Permian System. The Permian-Triassic boundary is an unconformity corresponding to both erosional and non-depositional hiatuses. The gap at the Permian-Triassic boundary partially corresponds to the shelf-margin systems tract and partly to the transgressive systems tract of the overlying third-order sequence. Stromatolites are interpreted as transgressive systems tract deposits. Special issueInternational Conference on Paleozoic Foraminifera, Paleoforams 2001Edited by Demir Altiner (Guest Editor
Wildbook: Crowdsourcing, computer vision, and data science for conservation
Photographs, taken by field scientists, tourists, automated cameras, and
incidental photographers, are the most abundant source of data on wildlife
today. Wildbook is an autonomous computational system that starts from massive
collections of images and, by detecting various species of animals and
identifying individuals, combined with sophisticated data management, turns
them into high resolution information database, enabling scientific inquiry,
conservation, and citizen science.
We have built Wildbooks for whales (flukebook.org), sharks (whaleshark.org),
two species of zebras (Grevy's and plains), and several others. In January
2016, Wildbook enabled the first ever full species (the endangered Grevy's
zebra) census using photographs taken by ordinary citizens in Kenya. The
resulting numbers are now the official species census used by IUCN Red List:
http://www.iucnredlist.org/details/7950/0. In 2016, Wildbook partnered up with
WWF to build Wildbook for Sea Turtles, Internet of Turtles (IoT), as well as
systems for seals and lynx. Most recently, we have demonstrated that we can now
use publicly available social media images to count and track wild animals.
In this paper we present and discuss both the impact and challenges that the
use of crowdsourced images can have on wildlife conservation.Comment: Presented at the Data For Good Exchange 201
Growth and reproduction studies on gilthead seabream (Sparus aurata) in Beymelek Lagoon, Turkey
In the present study, age, growth, length-weight relationship and reproduction were investigated in gilthead seabream (Sparus aurata L., 1758) collected from Beymelek Lagoon (Antalya, Turkey) between February 2006 and July 2007. The age, total length and weight of samples ranged from 0+ to 4 years, 10.6 to 35.5cm, and 18 to 928g, respectively. Growth was described by the standard form of the von Bertalanffy growth equation and the estimated parameters were L∞ = 44.6cm, k = 0.394yr^-1 and t0 = -1.331yr. Length-weight relationship was determined as W=0.0174TL^2.9769 (R^2=0.965), and weight increased with size isometrically (b = 2.9769) for all fish. Sex inversion occurred mainly at 26 cm in total length and females reached sexual maturity at 28.5 cm. The spawning period was from December to February, while the gamete emission peaked in December
Protein and gene delivery systems for neurodegenerative disorders: Where do we stand today?
It has been estimated that every year, millions of people are affected by neurodegenerative disorders, which complicate their lives and their caregivers’ lives. To date, there has not been an approved pharmacological approach to provide the complete treatment of neurodegenerative disorders. The only available drugs may only relieve the symptoms or slow down the progression of the disease. The absence of any treatment is quite rational given that neurodegeneration occurs by the progressive loss of the function or structure of the nerve cells of the brain or the peripheral nervous system, which eventually leads to their death either by apoptosis or necrotic cell death. According to a recent study, even though adult brain cells are injured, they can revert to an embryonic state, which may help to restore their function. These interesting findings might open a new path for the development of more efficient therapeutic strategies to combat devastating neurodegenerative disorders. Gene and protein therapies have emerged as a rapidly growing field for various disorders, especially neurodegenerative diseases. Despite these promising therapies, the complete treatment of neurodegenerative disorders has not yet been achieved. Therefore, the aim of this review is to address the most up-to-date data for neurodegenerative diseases, but most importantly, to summarize the available delivery systems incorporating proteins, peptides, and genes that can potentially target such diseases and pass into the blood–brain barrier. The authors highlight the advancements, at present, on delivery based on the carrier, i.e., lipid, polymeric, and inorganic, as well as the recent studies on radiopharmaceutical theranostics
- …