Pleurisy secondary to nonthrombotic pulmonary emboli in a patient with intravenous drug use.

Patients with injection drug use can have nonthrombotic pulmonary emboli (NTPE) of foreign insoluble particles that are either parts of the equipment used or mixed with the drug as an additive. These foreign particles can become a nidus for infection and inflammation. We present a case of a 31-year-old man with active intravenous drug use who initially presented with signs and symptoms of pleurisy and was found to have NTPE of septic refractile crystalline material as seen on bronchial wash and brush biopsy. We believe our patient likely had embolism of either crack particles, needle fragments or cotton-wool fragments that led to a localized inflammatory reaction and infection. This highlights the importance of obtaining detailed history and diagnostic workup. Once the diagnoses of bacterial endocarditis and thrombophlebitis are ruled out with blood cultures, transthoracic echocardiogram, trans-esophageal echocardiogram and/or CT scan (depending on the suspicion), NTPE should be considered and bronchoscopy with bronchoalveolar lavage with biopsy should be performed.

A Case of Adult Clival Osteomyelitis.

Clival osteomyelitis is a potentially life-threatening skull base infection. It is rare and generally challenging to diagnose and treat. Clival osteomyelitis is typically seen in the pediatric population and is very rare in the adult population. It occurs as a complication of recurring paranasal infections and malignant otitis externa. The exact pathophysiology of osteomyelitis of the clivus is relatively uncertain. Here, we describe a case of a 36-year-old man with medical history significant for hypertension and poorly controlled type 1 diabetes mellitus who experienced recurrent paranasal sinus infection for 2 years. He received multiple antibiotic treatments and underwent adenoidectomy without substantial improvement of symptoms. Ultimately, a diagnosis of the clival osteomyelitis through the help of a computed tomography (CT) scan of the paranasal sinus and neck was made. This diagnosis allowed for adequate intervention and treatment of our patient with subsequent resolution of his presenting symptoms. This case highlights the importance of high suspicion for clival osteomyelitis in patients with recurring sinus infections.

Temporary Exclusion of Cattle from a Riparian Zone Using Virtual Fencing Technology.

Grazing cattle can both negatively and positively impact riparian zones, dependent on controlled grazing management. Virtual fencing technology, using collar devices that operate via GPS can provide audio cues and electrical stimuli to temporarily exclude cattle from specified areas as desired. An early experimental prototype automated virtual fencing system was tested in excluding ten cattle from a riparian zone in Australia. Animals were given free access to an 11.33-hectare area for three weeks, excluded from river access by a virtual fence for ten days (2.86-hectare inclusion zone), followed by free access again for six days. Animals were almost exclusively contained by the virtual fence. All animals received audio cues and electrical stimuli with daily fence interactions, but there was high individual variation with some animals first approaching the fence more often than others. Overall, there was an approximately 25% probability that animals would receive an electrical stimulus following an audio cue. Individual associative learning may have been socially-facilitated by the group's behaviour. Following fence deactivation, all animals re-entered the previously excluded area. Further research with more groups and longer periods of exclusion using updated collar devices would determine the scope of virtual fencing technology for cattle grazing control.

Tech-Savvy Beef Cattle? How Heifers Respond to Moving Virtual Fence Lines.

Global Positioning System (GPS)-based virtual fences offer the potential to improve the management of grazing animals. Prototype collar devices utilising patented virtual fencing algorithms were placed on six Angus heifers in a 6.15 hectare paddock. After a "no fence" period, sequential, shifting virtual fences restricted the animals to 40%, 60%, and 80% of the paddock area widthways and 50% lengthways across 22 days. Audio cues signaled the virtual boundary, and were paired with electrical stimuli if the animals continued forward into the boundary. Within approximately 48 h, the cattle learned the 40% fence and were henceforth restricted to the subsequent inclusion zones a minimum of 96.70% (±standard error 0.01%) of the time. Over time, the animals increasingly stayed within the inclusion zones using audio cues alone, and on average, approached the new fence within 4.25 h. The animals were thus attentive to the audio cue, not the fence location. The time spent standing and lying and the number of steps were similar between inclusion zones (all p ≥ 0.42). More lying bouts occurred at the 80% and lengthways inclusion zones relative to "no fence" (p = 0.04). Further research should test different cattle groups in variable paddock settings and measure physiological welfare responses to the virtual fencing stimuli.