Genetic evidence for widespread population size expansion in North American boreal birds prior to the Last Glacial Maximum.

Pleistocene climate cycles are well documented to have shaped contemporary species distributions and genetic diversity. Northward range expansions in response to deglaciation following the Last Glacial Maximum (LGM; approximately 21 000 years ago) are surmised to have led to population size expansions in terrestrial taxa and changes in seasonal migratory behaviour. Recent findings, however, suggest that some northern temperate populations may have been more stable than expected through the LGM. We modelled the demographic history of 19 co-distributed boreal-breeding North American bird species from full mitochondrial gene sets and species-specific molecular rates. We used these demographic reconstructions to test how species with different migratory strategies were affected by glacial cycles. Our results suggest that effective population sizes increased in response to Pleistocene deglaciation earlier than the LGM, whereas genetic diversity was maintained throughout the LGM despite shifts in geographical range. We conclude that glacial cycles prior to the LGM have most strongly shaped contemporary genetic diversity in these species. We did not find a relationship between historic population dynamics and migratory strategy, contributing to growing evidence that major switches in migratory strategy during the LGM are unnecessary to explain contemporary migratory patterns.

Covid-19 presenting as a bulging fontanelle.

The 2019 novel coronavirus disease (COVID-19) has become a global pandemic that has struck the United States particularly hard. While it has disproportionately caused severe illness in the elderly and older adult population, many children have also been infected with the virus and some have become critically ill. It is important to recognize COVID-19 may present differently in children; specifically, those under twelve months of age. We report a case of COVID-19 infection in an infant characterized by a bulging anterior fontanelle without any additional symptoms.

Predictors of safe discharge for pediatric drowning patients in the emergency department.

OBJECTIVES: The purpose of this study is to determine if stable, well-appearing, drowning patients who have normal age-adjusted vital signs and pulse oximetry upon arrival to the emergency department may be safely discharged without a prolonged observation period. METHODS: Medical records were retrospectively reviewed for drowning patients presenting to a single pediatric emergency department from 1995 to 2014. Data were collected on vital signs and pulse oximetry at presentation, chest x-ray results, disposition and complications for each encounter. Patients were identified as having either normal or abnormal initial vital signs and pulse oximetry, and were compared based on disposition and complication rates. RESULTS: Two hundred seventy-six records were initially evaluated and 91 were excluded. Thirty-six percent had normal age-adjusted vital signs upon arrival. Patients with abnormal temperature, respiratory rate or pulse oximetry, as well as those with any abnormal initial cardiopulmonary physical exam findings, abnormal mental status, or chest radiograph findings, were more likely to be admitted to the hospital. Eight patients developed respiratory complications after presentation to the emergency department. Those with abnormal pulse oximetry readings on arrival were more likely to develop complications. Only two patients who developed complications had initially normal vital signs and each had evidence of clinical deterioration within 1h of arrival. CONCLUSIONS: The overall complication rate in initially stable, well-appearing drowning patients is low. An abnormal pulse oximetry reading at presentation may help predict subsequent complications. Those patients with normal age-adjusted vital signs and physical exam at presentation may not require a prolonged observation period.

Management Of Fever And Suspected Infection In Pediatric Patients With Central Venous Catheters.

The use of indwelling central venous catheters is essential for pediatric patients who require hemodialysis, parenteral nutrition, chemotherapy, or other medications. Fever is a common chief complaint in the emergency department, and fever in a patient with a central venous catheter may be related to a common cause of fever, or it may be due to a catheter-associated bloodstream infection. Catheter-associated bloodstream infections may also lead to additional complications such as sepsis, septic shock, or septic complications including suppurative thrombophlebitis, endocarditis, osteomyelitis, septic emboli, and abscesses. Early resuscitation as well as timely and appropriate antibiotic therapy have been shown to improve outcomes. This issue focuses on the approach to fever in pediatric patients with central venous catheters and the management and disposition of patients with possible catheter-associated bloodstream infections.

Convenient method of synthesizing 3-ethoxycarbonyl indoles.

We have developed a convenient two-step procedure for the synthesis of 3-ethoxycarbonyl indoles from commercially available materials. The two-step procedure involves the synthesis of 2-aryl-3-hydroxypropenoic acid ester, followed by a catalytic reduction. This method is efficient, simple, and selective.

Acid-catalyzed reactions of aromatic aldehydes with ethyl diazoacetate: an investigation on the synthesis of 3-hydroxy-2-arylacrylic acid ethyl esters.

Several commercial Lewis acids, including those of the Bronsted type, specifically HBF(4).OEt(2), are able to catalyze the reaction between aromatic aldehydes and ethyl diazoacetate to produce 3-hydroxy-2-arylacrylic acid ethyl esters and 3-oxo-3-arylpropanoic acid ethyl esters. Reactions catalyzed by the iron Lewis acid [(eta(5)-C(5)H(5))Fe(+)(CO)(2)(THF)]BF(4)(-) (i.e., 1) have the best yields and greatest ratio of 3-hydroxy-2-arylacrylic acid ethyl ester. The product distribution of 1 is not affected in the presence of Proton Sponge, but is dependent on temperature and the nature of the substrate aldehyde, whereas the activity of HBF(4).OEt(2) is affected by the presence of Proton Sponge and is reactive at temperatures as low as -78 degrees C. Consequently, both 1 and HBF(4).OEt(2) are valuable catalysts in producing important 3-hydroxy-2-arylacrylic acid ethyl esters as precursors to biologically active compounds.