What blood tests help diagnose celiac disease?

Histological confirmation of infiltrative lesions via small bowel biopsy is the gold standard for diagnosing celiac disease. Four serum antibody assays may serve as a first- step diagnostic tool to identify biopsy candidates: immunoglobulin A tissue transglutaminase (IgA tTG), IgA endomysial antibody (IgA EMA), IgA antigliadin antibody (IgA AGA), and IgG antigliadin antibody (IgG AGA). IgA tTG and IgA EMA offer the best diagnostic accuracy. Patients with selective IgA deficiency may have falsely negative IgA assays (strength of recommendation [SOR]: B, based on a systematic review, multiple small cross-sectional studies, and expert opinion)

A new proof that alternating links are non-trivial

We use a simple geometric argument and small cancellation properties of link groups to prove that alternating links are non-trivial. This proof uses only classic results in topology and combinatorial group theory.Comment: Minor changes. To appear in Fundamenta Mathematica

Late Cretaceous Dinosaur Tracks from the Iron Springs Formation, Iron County, Utah

Located in Iron County, Utah, the Parowan Gap dinosaur track site contains over one hundred natural casts of non-avian dinosaur tracks preserved in sandstones and siltstones of the Late Cretaceous (≈83 Ma) Iron Springs Formation. For this study, the authors returned to the area to survey for and describe previously unidentified tracks. Many tracks from this new study occur as in situ casts found on the basal surfaces of sandstones deposited by braided and meandering rivers on the coastal plain of the Western Interior Seaway, with some specimens from fallen talus blocks. Over the course of two years, the research team identified and recorded a total of 31 specimens. The results comprise tracks that resemble a minimum of at least five ichnotaxa including Caririchnium, Amblydactylus, Ceratopsipes, Magnoavipes, and Dromaeosauripus. The most common and well-recognized ichnogenus recorded in the Iron Springs Formation is Caririchnium, which likely represents ornithopod dinosaurs. We also identified two Ceratopsipes tracks in a fallen sandstone block. The pair of tracks are significant because they are the second set from the ichnotaxa found at Parowan Gap. Together the Parowan Gap Ceratopsipes samples represent the oldest ceratopsian tracks in Utah. The potential Dromaeosauripus specimen represents a small theropod dinosaur. This specimen is of great interest because theropod tracks, especially dromaeosaur tracks, are less common in the Iron Springs Formation, with a total of seven tracks reported from previous studies. If this is an appropriate interpretation, it would make the potential Dromaeosauripus track the youngest dromaeosaur trace fossil in Utah

Poverty, Literacy, and Social Transformation: An Interdisciplinary Exploration of the Digital Divide

Harnessing scholarship focused on literacy and poverty, in this article we aim to complicate the common understanding of the digital divide. First, we argue that the dominant literature on the digital divide misses broader connections between technological exclusion and broader forms of economic and social exclusion. Accordingly, and following recent qualitative research on the digital divide, we believe future scholarship must examine the complicated relationships between poverty, inequality, and the digital divide and we look to poverty scholarship to understand the complicated and shifting nature of poverty. Finally, we make the case that scholars and practitioners focused on digital literacy programs should pay attention to historical and critical scholarship on education and its role in mediating poverty and fostering social mobility, as it serves digital divide and broadband adoption scholars to understand the ways education processes can either reproduce or set the stage to alter entrenched social realities

A STUDY OF EXTRACELLULAR SPACE IN CENTRAL NERVOUS TISSUE BY FREEZE-SUBSTITUTION

It was attempted to preserve the water distribution in central nervous tissue by rapid freezing followed by substitution fixation at low temperature. The vermis of the cerebellum of white mice was frozen by bringing it into contact with a polished silver mirror maintained at a temperature of about -207°C. The tissue was subjected to substitution fixation in acetone containing 2 per cent OsO4 at -85°C for 2 days, and then prepared for electron microscopy by embedding in Maraglas, sectioning, and staining with lead citrate or uranyl acetate and lead. Cerebellum frozen within 30 seconds of circulatory arrest was compared with cerebellum frozen after 8 minutes' asphyxiation. From impedance measurements under these conditions, it could be expected that in the former tissue the electrolyte and water distribution is similar to that in the normal, oxygenated cerebellum, whereas in the asphyxiated tissue a transport of water and electrolytes into the intracellular compartment has taken place. Electron micrographs of tissue frozen shortly after circulatory arrest revealed the presence of an appreciable extracellular space between the axons of granular layer cells. Between glia, dendrites, and presynaptic endings the usual narrow clefts and even tight junctions were found. Also the synaptic cleft was of the usual width (250 to 300 A). In asphyxiated tissue, the extracellular space between the axons is either completely obliterated (tight junctions) or reduced to narrow clefts between apposing cell surfaces

The Effects of Prolonged Job Insecurity on the Psychological Well-Being of Workers

Job insecurity has been increasing since the 1980s. While researchers have found job insecurity to be negatively associated with multiple indicators of well-being for workers and their families in cross sectional studies, less is known about the long term effects of prolonged job insecurity. Specifically, there is a need to collect measures of both insecurity and its consequences at multiple time periods. The current study followed workers for 3 1/2 years to assess the effects of chronic job insecurity on psychological distress. Results indicate that while workers reported increased feelings of security over time, there were longer term negative effects on workers\u27 depression levels. The importance of government regulations to decrease insecurity is discussed

Homogeneous links, Seifert surfaces, digraphs and the reduced Alexander polynomial

We give a geometric proof of the following result of Juhasz. \emph{Let $a_g$ be the leading coefficient of the Alexander polynomial of an alternating knot $K$. If $|a_g|<4$ then $K$ has a unique minimal genus Seifert surface.} In doing so, we are able to generalise the result, replacing `minimal genus' with `incompressible' and `alternating' with `homogeneous'. We also examine the implications of our proof for alternating links in general.Comment: 37 pages, 28 figures; v2 Main results generalised from alternating links to homogeneous links. Title change