3,953 research outputs found
Mechanical Instabilities of Biological Tubes
We study theoretically the shapes of biological tubes affected by various
pathologies. When epithelial cells grow at an uncontrolled rate, the negative
tension produced by their division provokes a buckling instability. Several
shapes are investigated : varicose, enlarged, sinusoidal or sausage-like, all
of which are found in pathologies of tracheal, renal tubes or arteries. The
final shape depends crucially on the mechanical parameters of the tissues :
Young modulus, wall-to-lumen ratio, homeostatic pressure. We argue that since
tissues must be in quasistatic mechanical equilibrium, abnormal shapes convey
information as to what causes the pathology. We calculate a phase diagram of
tubular instabilities which could be a helpful guide for investigating the
underlying genetic regulation
Pasture top-dressing in New Hampshire, Bulletin, no. 320
The Bulletin is a publication of the New Hampshire Agricultural Experiment Station, College of Life Sciences and Agriculture, University of New Hampshire, Durham, New Hampshire
Attempts to Identify Wildlife Reservoirs of Rabies in Indonesia
Penyakit rabies telah dikenal di Indonesia sejak tahun 1889, dan mengingat tidak adanya data yang diteliti mengenai penderita rabies, maka perlu dilakukan suatu penelitian. Penelitian dilakukan oleh NAMRU-2 bersama Departemen Kesehatan dari tahun 1970-1972 untuk menentukan pengaruh penyakit-penyakit Zoonotic yang endemic pada penduduk yang tidak immune yang sering berpindah ke hutan atau tempat yang tidak ada penduduknya. Penelitian di lakukan pada beberapa daerah pegunungan Jawa Barat, Jawa Timur, Lampung, Maluku, Kalimantan Tengah, Timor dan Sulawesi Tengah. Hasil penelitian menunjukkan bahwa dari 328 binatang yang diperoleh dari 28 berbagai daerah di Indonesia setelah diadakan pemeriksaan dengan metode fluorecent antibody technique {fat) dan inokuler pada tikus putih ternyata tidak ditemukan virus rabies. Binatang-binatang yang ditemukan tersebut dan kebiasaan hidupnya di lukiskan secara terperinci pada hasil penelitian ini
The Higgs Sector and CoGeNT/DAMA-Like Dark Matter in Supersymmetric Models
Recent data from CoGeNT and DAMA are roughly consistent with a very light
dark matter particle with m\sim 4-10\gev and spin-independent cross section
of order \sigma_{SI} \sim (1-3)\times 10^{-4}\pb. An important question is
whether these observations are compatible with supersymmetric models obeying
without violating existing collider constraints and
precision measurements. In this talk, I review the fact the the Minimal
Supersymmetric Model allows insufficient flexibility to achieve such
compatibility, basically because of the highly constrained nature of the MSSM
Higgs sector in relation to LEP limits on Higgs bosons. I then outline the
manner in which the more flexible Higgs sectors of the Next-to-Minimal
Supersymmetric Model and an Extended Next-to-Minimal Supersymmetric Model allow
large and at low LSP mass without violating
LEP, Tevatron, BaBar and other experimental limits. The relationship of the
required Higgs sectors to the NMSSM "ideal-Higgs" scenarios is discussed.Comment: 11 pages, 3 figures. To appear in Proceedings of PASCOS 2010. The
paper is a compilation of talks given at: PASCOS 2010, ORSAY Workshop on
"Higgs Hunting", and SLAC Workshop on "Topologies for Early LHC Searches
Computational Relativistic Astrophysics With Adaptive Mesh Refinement: Testbeds
We have carried out numerical simulations of strongly gravitating systems
based on the Einstein equations coupled to the relativistic hydrodynamic
equations using adaptive mesh refinement (AMR) techniques. We show AMR
simulations of NS binary inspiral and coalescence carried out on a workstation
having an accuracy equivalent to that of a regular unigrid simulation,
which is, to the best of our knowledge, larger than all previous simulations of
similar NS systems on supercomputers. We believe the capability opens new
possibilities in general relativistic simulations.Comment: 7 pages, 16 figure
Magnetic properties of submicron Co islands and their use as artificial pinning centers
We report on the magnetic properties of elongated submicron magnetic islands
and their influence on a superconducting film. The magnetic properties were
studied by magnetization hysteresis loop measurements and scanning-force
microscopy. In the as-grown state, the islands have a magnetic structure
consisting of two antiparallel domains. This stable domain configuration has
been directly visualized as a 2x2-checkerboard pattern by magnetic-force
microscopy. In the remanent state, after magnetic saturation along the easy
axis, all islands have a single-domain structure with the magnetic moment
oriented along the magnetizing field direction. Periodic lattices of these Co
islands act as efficient artificial pinning arrays for the flux lines in a
superconducting Pb film deposited on top of the Co islands. The influence of
the magnetic state of the dots on their pinning efficiency is investigated in
these films, before and after the Co dots are magnetized.Comment: 6 pages including figure
Field, capital and the policing habitus: nderstanding Bourdieu through The NYPD’s post-9/11 counterterrorism practices
This article extends existing Bourdieusian theory in criminology and
security literature through examining the practices of the New York City
Police Department in the post-9/11 counterterrorism field. This article
makes several original contributions. First, it explores the resilient nature
of the policing habitus, extending Bourdieusian criminological findings
that habitus are entrenched and difficult to change. Second, this article
examines the way the resilient habitus drives subordinate factions to
displace dominant factions in a field’s established social hierarchy
through boundary-pushing practices, a concept previously unexamined in
Bourdieusian criminology. Drawing on original documentary analysis, this
article uses the illustrative example of the NYPD’s post-9/11
counterterrorism practices, exploring how it sought to displace the
existing social structure by using its aggressive policing habitus and an
infusion of ‘War on Terror’ capital to challenge the dominant position of
the FBI in the post-9/11 counterterrorism field. The NYPD’s habitus
driven counterterrorism practices were novel and unprecedented,
creating strain with both the FBI and local communities
Three-dimensional adaptive evolution of gravitational waves in numerical relativity
Adaptive techniques are crucial for successful numerical modeling of
gravitational waves from astrophysical sources such as coalescing compact
binaries, since the radiation typically has wavelengths much larger than the
scale of the sources. We have carried out an important step toward this goal,
the evolution of weak gravitational waves using adaptive mesh refinement in the
Einstein equations. The 2-level adaptive simulation is compared with unigrid
runs at coarse and fine resolution, and is shown to track closely the features
of the fine grid run.Comment: REVTeX, 7 pages, including three figures; submitted to Physical
Review
Attribution of the human influence on heavy rainfall associated with flooding events during the 2012, 2016, and 2018 March-April-May seasons in Kenya
The changing probabilities of extreme climate and weather events, in terms of frequency, intensity, spatial extent, duration, and timing is one of the most noticeable and damaging manifestations of human-induced climate change. During the March-April-May (MAM) rainfall season of 2012, 2016 and 2018, Kenya experienced high rainfall that caused both widespread and localised flooding, resulting in human and livestock deaths, destruction of infrastructure and property, bursting of riverbanks, submerging of farmlands and emergence of isolated cases of water-borne diseases. Here, we aim to quantify how the magnitude of heavy rainfall during these seasons may have been altered by human-induced climate change. We undertake a probabilistic attribution analysis using three different approaches utilising two observational datasets and two independent climate model experiment set-ups. We analyse three different seasonal heavy rainfall indices, maximum consecutive 5-day, 10-day, and 20-day rainfall, to compare the magnitude of maxima recorded in MAM 2012, 2016 and 2018 with the magnitude of maxima in a pre-industrial climate (with little or no anthropogenic influence). We find a shift towards intensification of extreme rainfall in today's climate, although these increases are not in all cases statistically distinguishable from our estimates of magnitudes in the preindustrial climate. Although we find no significant anthropogenic climate change influence, the intensification of extreme rainfall amid the observed drying trend and the projected increases in rainfall in the MAM season in Kenya, leave the already vulnerable societies with uncertainties about how to prepare for a changing climate. This study, therefore, provides a basis for an in-depth assessment of current and future trends of extreme rainfall in East Africa in adapting to changing climate risks for sustainable development in the already vulnerable and less resilient society
Molecular genetics and pathophysiology of 17 beta-hydroxysteroid dehydrogenase 3 deficiency.
Autosomal recessive mutations in the 17 beta-hydroxysteroid dehydrogenase 3 gene impair the formation of testosterone in the fetal testis and give rise to genetic males with female external genitalia. Such individuals are usually raised as females, but virilize at the time of expected puberty as the result of increases in serum testosterone. Here we describe mutations in 12 additional subjects/families with this disorder. The 14 mutations characterized to date include 10 missense mutations, 3 splice junction abnormalities, and 1 small deletion that results in a frame shift. Three of these mutations have occurred in more than 1 family. Complementary DNAs incorporating 9 of the 10 missense mutations have been constructed and expressed in reporter cells; 8 of the 9 missense mutations cause almost complete loss of enzymatic activity. In 2 subjects with loss of function, missense mutations testosterone levels in testicular venous blood were very low. Considered together, these findings strongly suggest that the common mechanism for testosterone formation in postpubertal subjects with this disorder is the conversion of circulating androstenedione to testosterone by one or more of the unaffected 17 beta-hydroxysteroid dehydrogenase isoenzymes
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