1,716 research outputs found
Checkerboards, stripes and corner energies in spin models with competing interactions
We study the zero temperature phase diagram of Ising spin systems in two
dimensions in the presence of competing interactions, long range
antiferromagnetic and nearest neighbor ferromagnetic of strength J. We first
introduce the notion of a "corner energy" which shows, when the
antiferromagnetic interaction decays faster than the fourth power of the
distance, that a striped state is favored with respect to a checkerboard state
when J is close to J_c, the transition to the ferromagnetic state, i.e., when
the length scales of the uniformly magnetized domains become large. Next, we
perform detailed analytic computations on the energies of the striped and
checkerboard states in the cases of antiferromagnetic interactions with
exponential decay and with power law decay r^{-p}, p>2, that depend on the
Manhattan distance instead of the Euclidean distance. We prove that the striped
phase is always favored compared to the checkerboard phase when the scale of
the ground state structure is very large. This happens for J\lesssim J_c if
p>3, and for J sufficiently large if 2<p<=3. Many of our considerations
involving rigorous bounds carry over to dimensions greater than two and to more
general short-range ferromagnetic interactions.Comment: 21 pages, 3 figure
Selective Inguinal Lymphadenectomy in the Treatment of Invasive Squamous Cell Carcinoma of the Vulva
En bloc radical vulvectomy with bilateral inguinofemoral lymphadenectomy has now been replaced by radical wide excision and selective inguinal lymphadenectomy based on the stage and location of invasive vulvar cancer. Early stage lateral cancers can be effectively treated by radical wide excision and ipsilateral superficial inguinal lymphadenectomy. Lymph node mapping using perilesional injection of radiocolloid and blue dye may identify sentinel lymph nodes which can be removed, thereby avoiding the morbidity of full inguinal lymphadenectomy in selected patients with early stage disease
A Source for Feature-Based Attention in the Prefrontal Cortex
SummaryIn cluttered scenes, we can use feature-based attention to quickly locate a target object. To understand how feature attention is used to find and select objects for action, we focused on the ventral prearcuate (VPA) region of prefrontal cortex. In a visual search task, VPA cells responded selectively to search cues, maintained their feature selectivity throughout the delay and subsequent saccades, and discriminated the search target in their receptive fields with a time course earlier than in FEF or IT cortex. Inactivation of VPA impaired the animals’ ability to find targets, and simultaneous recordings in FEF revealed that the effects of feature attention were eliminated while leaving the effects of spatial attention in FEF intact. Altogether, the results suggest that VPA neurons compute the locations of objects with the features sought and send this information to FEF to guide eye movements to those relevant stimuli
Identification of the hyaluronic acid pathway as a therapeutic target for facioscapulohumeral muscular dystrophy
Facioscapulohumeral muscular dystrophy (FSHD) is linked to epigenetic derepression of the germline/embryonic transcription factor DUX4 in skeletal muscle. However, the etiology of muscle pathology is not fully understood, as DUX4 misexpression is not tightly correlated with disease severity. Using a DUX4-inducible cell model, we show that multiple DUX4-induced molecular pathologies that have been observed in patient-derived disease models are mediated by the signaling molecule hyaluronic acid (HA), which accumulates following DUX4 induction. These pathologies include formation of RNA granules, FUS aggregation, DNA damage, caspase activation, and cell death. We also observe previously unidentified pathologies including mislocalization of mitochondria and the DUX4- and HA-binding protein C1QBP. These pathologies are prevented by 4-methylumbelliferone, an inhibitor of HA biosynthesis. Critically, 4-methylumbelliferone does not disrupt DUX4-C1QBP binding and has only a limited effect on DUX4 transcriptional activity, establishing that HA signaling has a central function in pathology and is a target for FSHD therapeutics
Nucleophilic Displacements in Supercritical Carbon Dioxide using Silica Supported Phase-Transfer Agents
Violence against Women Raises Risk of Cervical Cancer
Background: An emerging literature suggests that violence against women (VAW), particularly sexual violence, may increase the risk of acquiring a sexually transmitted infection (STI) and, therefore, may be associated with cervical cancer development. The purpose of this cross-sectional analysis was to determine if women who had experienced violence had higher prevalence rates of invasive cervical cancer.
Methods: Women aged 18–88 who joined the Kentucky Women’s Health Registry (2006–2007) and completed a questionnaire were included in the sample. Multivariate logistic regression analyses were used to adjust odds ratio (OR) for confounders (e.g., age, education, current marital status, lifetime illegal drug use, and pack-years of cigarette smoking).
Results: Of 4732 participants with no missing data on violence, cervical cancer, or demographic factors, 103 (2.1%) reported ever having cervical cancer. Adjusting for demographic factors, smoking, and illegal drug use, experiencing VAW was associated with an increased prevalence of invasive cervical cancer (adjusted OR [aOR]¼2.6, 95% CI¼1.7-3.9). This association remained significant when looking at three specific types of VAW: intimate partner violence (IPV) (aOR¼2.7, 95% CI¼1.8-4.0), adult exposure to forced sex (aOR¼2.6, 95% CI¼1.6-4.3), and child exposure to sexual abuse (aOR¼2.4, 95% CI¼1.4-4.0).
Conclusions: Rates of cervical cancer were highest for those experiencing all three types of VAW relative to those never experiencing VAW. Because VAW is common and has gynecological health effects, asking about VAW in healthcare settings and using this information to provide tailored healthcare may improve women’s health outcomes
Fabrication of multiphasic and regio-specifically functionalized PRINT ® particles of controlled size and shape
Using Particle Replication In Nonwetting Templates (PRINT®) technology, multiphasic and regio-specifically functionalized shape-controlled particles have been fabricated that include end-labeled particles via post-functionalization; biphasic Janus particles that integrate two compositionally different chemistries into a single particle; and more complex multiphasic shape-specific particles. Controlling the anisotropic distribution of matter within a particle creates an extra parameter in the colloidal particle design, providing opportunities to generate advanced particles with versatile and tunable compositions, properties, and thus functionalities. Owing to their robust characteristics, these multiphasic and regio-specifically functionalized PRINT particles should be promising platforms for applications in life science and materials science
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