Radiographic diagnosis of small intestinal obstruction in pet rabbits (Oryctolagus cuniculus): 63 cases

OBJECTIVES

To identify radiographic features that can be used to aid in the diagnosis of small intestinal obstruction in pet rabbits.

MATERIALS AND METHODS

Retrospective study comparing radiographic features of 63 cases of confirmed intestinal obstruction with 50 abdominal radiographs taken of rabbits without gastrointestinal disease. Abdominal radiographs were examined for gastric size, gastric contents, small intestinal dilatation and gas within the large intestine and caecum.

RESULTS

Gastric size, gastric contents, small intestinal dilatation and gas within the large intestine and caecum were all features that differed between rabbits with small intestinal obstruction and rabbits without gastrointestinal disease. Radiographic features associated with small intestinal obstruction included severe gastric dilation, gastric contents primarily consisting of liquid and gas, small intestinal dilation and absence of large amounts of gas in the caecum and large intestine.

CLINICAL SIGNIFICANCE

Observation on gastric size, small intestinal dilatation and gas within the large intestine and caecum aid in radiological diagnosis of small intestinal obstruction in rabbits and so can guide appropriate treatment.

Kinetic effects regularize the mass-flux singularity at the contact line of a thin evaporating drop

We consider the transport of vapour caused by the evaporation of a thin, axisymmetric, partially wetting drop into an inert gas. We take kinetic effects into account through a linear constitutive law that states that the mass flux through the drop surface is proportional to the difference between the vapour concentration in equilibrium and that at the interface. Provided that the vapour concentration is finite, our model leads to a finite mass flux in contrast to the contact-line singularity in the mass flux that is observed in more standard models that neglect kinetic effects. We perform a local analysis near the contact line to investigate the way in which kinetic effects regularize the mass-flux singularity at the contact line. An explicit expression is derived for the mass flux through the free surface of the drop. A matched-asymptotic analysis is used to further investigate the regularization of the mass-flux singularity in the physically relevant regime in which the kinetic timescale is much smaller than the diffusive one. We find that the effect of kinetics is limited to an inner region near the contact line, in which kinetic effects enter at leading order and regularize the mass-flux singularity. The inner problem is solved explicitly using the Wiener-Hopf method and a uniformly valid composite expansion is derived for the mass flux in this asymptotic limit.

Self-Referent Versus Other-Referent Information Processing in Dysphoric, Clinically Depressed, and Remitted Depressed Subjects

Two studies examined the processing of responses directed toward the self versus others by dysphoric, clinically depressed, and remitted depressed subjects. Study 1 showed that dysphoric subjects found positive and negative responses toward the self equally informative. Nondysphoric subjects found positive responses toward the self more informative than negative responses. When responses were directed toward others, dysphoric subjects found positive responses more informative than negative responses. In contrast, nondysphoric subjects found positive and negative responses directed toward others equally informative. Study 2 replicated these results with clinically depressed versus nondysphoric subjects. Study 2 also showed that remitted depressed subjects found positive responses more informative than negative responses, regardless of whether they were directed toward the self or toward others. Results suggest that positive and negative constructs are differentially accessible for dysphoric, clinically depressed, remitted depressed, and nondysphoric subjects when processing information directed toward the self versus others.

Inverse Leidenfrost Effect: Levitating Drops on Liquid Nitrogen

We explore the interaction between a liquid drop (initially at room temperature) and a bath of liquid nitrogen. In this scenario, heat transfer occurs through film-boiling: a nitrogen vapor layer develops that may cause the drop to levitate at the bath surface. We report the phenomenology of this inverse Leidenfrost effect, investigating the effect of the drop size and density by using an aqueous solution of a tungsten salt to vary the drop density. We find that (depending on its size and density) a drop either levitates or instantaneously sinks into the bulk nitrogen. We begin by measuring the duration of the levitation as a function of the radius R and density ρd of the liquid drop. We find that the levitation time increases roughly linearly with drop radius but depends weakly on the drop density. However, for sufficiently large drops, R ≥ Rc(ρd), the drop sinks instantaneously; levitation does not occur. This sinking of a (relatively) hot droplet induces film-boiling, releasing a stream of vapor bubbles for a well-defined length of time. We study the duration of this immersed-drop bubbling finding similar scalings (but with different prefactors) to the levitating drop case. With these observations, we study the physical factors limiting the levitation and immersed-film-boiling times, proposing a simple model that explains the scalings observed for the duration of these phenomena, as well as the boundary of (R,ρd) parameter space that separates them.

Capillary deformations of bendable films

We address the partial wetting of liquid drops on ultrathin solid sheets resting on a deformable foundation. Considering the membrane limit of sheets that can relax compression through wrinkling at negligible energetic cost, we revisit the classical theory for the contact of liquid drops on solids. Our calculations and experiments show that the liquid-solid-vapor contact angle is modified from the Young angle, even though the elastic bulk modulus (E) of the sheet is so large that the ratio between the surface tension γ and E is of molecular size. This finding indicates a new elastocapillary phenomenon that stems from the high bendability of very thin elastic sheets rather than from material softness. We also show that the size of the wrinkle pattern that emerges in the sheet is fully predictable, thus resolving a puzzle in modeling "drop-on-a-floating-sheet" experiments and enabling a quantitative, calibration-free use of this setup for the metrology of ultrathin films.

One case of fracture of the tibial tuberosity in the adult

The authors report a case of fracture of the anterior tibial tuberosity in an adult. The discussion involves the etiopathogenetic differences of fractures occurring in the adult, as compared to avulsion-fracture in the young patient. The individual features of an unusual direct trauma of the knee could explain the rareness of the clinical case presented.

Children's knowledge of thematic and taxonomic relations at two years of age

An interesting conflict exists in the developmental literature concerning the strength of thematic versus taxonomic associations. "Dog-doghouse" is a thematic match, while "dog-horse" is a taxonomic match. This study compared the ability of children to identify both types of associations at 2 points during the third year of life: 26 months (N = 15) and 34 months (N = 24). A reinforced match-to-sample technique was used in which half of the matches were thematic and the other half were taxonomic. Both age groups were able to identify thematic matches, although children near 3 years of age were able to recognize a wider range of thematic associations than children near 2 years of age. The 26-month-olds were unable to identify taxonomic matches that had no perceptual basis, but the 34-month-olds were successful at this task; the 34-month-olds appeared to have a more general understanding of categories that was less tied to perceptual features.