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Ice core measurements of the concentration and stable isotopic composition of atmospheric nitrous oxide (N2O) 74,000–59,000 years ago constrain marine and terrestrial emissions. The data include two major Dansgaard‐Oeschger (D‐O) events and the N2O decrease during global cooling at the Marine Isotope Stage (MIS) 5a‐4 transition. The N2O increase associated with D‐O 19 (~73–71.5 ka) was driven by equal contributions from marine and terrestrial emissions. The N2O decrease during the transition into MIS 4 (~71.5–67.5 ka) was caused by gradual reductions of similar magnitude in both marine and terrestrial sources. A 50 ppb increase in N2O concentration at the end of MIS 4 was caused by gradual increases in marine and terrestrial emissions between ~64 and 61 ka, followed by an abrupt increase in marine emissions at the onset of D‐O 16/17 (59.5 ka). This suggests that the importance of marine versus terrestrial emissions in controlling millennial‐scale N2O fluctuations varied in time. Plain Language Summary: Nitrous oxide is a powerful greenhouse gas that is produced naturally in soils and oceans. An important unresolved question is the extent to which anthropogenic warming will stimulate additional emissions from these sources, further adding to the warming. Past variations in the abundance of nitrous oxide have been observed using ice core reconstructions, but the reasons for the variations are not well understood. Nitrous oxide produced in soils is isotopically distinct from nitrous oxide produced in oceans. New measurements of the isotopes of atmospheric nitrous oxide provide constraints on how marine and terrestrial sources must have changed, driving fluctuations in nitrous oxide concentration during two intervals of rapid warming and a prolonged period of global cooling. The reconstructed changes in nitrous oxide sources provide insights into relationships between marine and terrestrial ecosystems and climate. Key Points: Stable isotopes of nitrous oxide constrain marine versus terrestrial production 74,000–59,000 years agoMarine and terrestrial sources varied similarly across Dansgaard‐Oeschger 19 and during the Marine Isotope Stage 5‐4 transitionMarine emissions dominated across Dansgaard‐Oeschger 16/17; thus, abrupt N2O increases were not all identical during the last glacial period [ABSTRACT FROM AUTHOR]

The continuous growth of atmospheric nitrous oxide (N2O) is of concern for its potential role in global warming and future stratospheric ozone destruction. Climate feedbacks that enhance N2O emissions in response to global warming are not well understood, and past records of N2O from ice cores are not sufficiently well resolved to examine the underlying climate‐N2O feedbacks on societally relevant time scales. Here, we present a new high‐resolution and high‐precision N2O reconstruction obtained from the Greenland NEEM (North Greenland Eemian Ice Drilling) and the Antarctic Styx Glacier ice cores. Covering the N2O history of the past two millennia, our reconstruction shows a centennial‐scale variability of ~10 ppb. A pronounced minimum at ~600 CE coincides with the reorganizations of tropical hydroclimate and ocean productivity changes. Comparisons with proxy records suggest association of centennial‐ to millennial‐scale variations in N2O with changes in tropical and subtropical land hydrology and marine productivity. Plain Language Summary: Nitrous oxide (N2O) is a greenhouse and ozone‐depleting gas. The growing level of N2O in the atmosphere is of global concern, and records of past N2O variations can provide an important context for understanding the links between N2O and climate change. In this study, we report new, high‐quality N2O records covering the last two millennia using ice cores obtained from Greenland and Antarctica. Our N2O records show rapid centennial‐scale changes in atmospheric N2O and confirm a pronounced minimum near 600 CE. Comparison with climate records suggests that hydroclimate change on land and changes in marine productivity contribute to centennial‐ to millennial‐scale N2O variations. Key Points: We report records of N2O concentration for the last 2,000 yr from the Styx ice core in Antarctca and NEEM ice core in GreenlandThe data accurately reveal the timing and magnitude of N2O variations on centennial time scalesVariations in N2O are associated with changes in tropical and subtropical land hydrology and marine productivity [ABSTRACT FROM AUTHOR]

Noble gases in ice cores enable reconstructions of past mean ocean temperature. A recent result from the clathrate‐containing WAIS Divide Ice Core showed tight covariation between ocean and Antarctic temperatures throughout the last deglaciation, except for the Younger Dryas interval. In the beginning of this interval, oceans warmed at 2.5 °C/kyr—three times greater than estimates of modern warming. If valid, this challenges our understanding of the mechanisms controlling ocean heat uptake. Here we reconstruct mean ocean temperature with clathrate‐free ice samples from Taylor Glacier to test these findings. The two records agree in net temperature change over the Younger Dryas, but the Taylor Glacier record suggests sustained warming at the more modest rate of 1.1 ± 0.2°C/kyr. We explore mechanisms to explain differences between records and suggest that the noble gas content for the Younger Dryas interval of WAIS Divide may have been altered by a decimeter‐scale fractionation during bubble‐clathrate transformation. Plain Language Summary: Oceans have taken up most of the additional heat trapped by greenhouse gases, mitigating the current rate of surface warming. In order to understand changes in ocean heat uptake over time, we use atmospheric noble gases measured in ice cores to estimate past ocean temperature change. This method works because the amount of noble gases dissolved in seawater changes with temperature. A recent ocean temperature reconstruction identified a 700‐year interval during the transition from the last ice age to the current warm period when oceans warmed three times faster than they are currently warming. This result challenged our understanding of how oceans warm as an ice age ends. We tested this finding with a new ice core record and found that ocean warming during this interval occurred at a rate that is comparable to today, which is more consistent with our understanding of ocean heat uptake. We suggest that the noble gas record in the original ice core was altered by a process that affects how atmospheric gases are distributed in ice and is unrelated to ocean temperature change. From these findings we suggest caution in interpreting noble gas records in ice cores where this process may occur. Key Points: A new Younger Dryas mean ocean temperature record shows significantly slower ocean heat uptake, compared to a previous reconstructionNoble gases are subject to fractionation during clathrate formation in glacial ice and thus errors in reconstructed mean ocean temperatureMean ocean temperature and Antarctic temperature covary through the entirety of the last deglaciation [ABSTRACT FROM AUTHOR]

Abstract: Changes in atmospheric CO2 on millennial‐to‐centennial timescales are key components of past climate variability during the last glacial and deglacial periods (70–10 ka), yet the sources and mechanisms responsible for the CO2 fluctuations remain largely obscure. Here we report the 13C/12C ratio of atmospheric CO2 during a key interval of the last glacial period at submillennial resolution, with coeval histories of atmospheric CO2, CH4, and N2O concentrations. The carbon isotope data suggest that the millennial‐scale CO2 variability in Marine Isotope Stage 3 is driven largely by changes in the organic carbon cycle, most likely by sequestration of respired carbon in the deep ocean. Centennial‐scale CO2 variations, distinguished by carbon isotope signatures, are associated with both abrupt hydrological change in the tropics (e.g., Heinrich events) and rapid increases in Northern Hemisphere temperature (Dansgaard‐Oeschger events). These events can be linked to modes of variability during the last deglaciation, thus suggesting that drivers of millennial and centennial CO2 variability during both periods are intimately linked to abrupt climate variability. [ABSTRACT FROM AUTHOR]

Abstract: Background: Children with developmental language disorders (DLDs) often struggle with classroom behaviour. No study has examined whether positive teacher–child relationships may act as a protective factor for children with DLDs in that these serve to enhance children's important classroom‐learning behaviours. Aims: To examine the association between the quality of teacher–child relationships and teacher‐rated classroom‐learning behaviours of children with DLDs in both preschool and kindergarten. Methods & Procedures: Longitudinal data were collected on 191 preschoolers (mean = 42.4 months of age, SD = 11.6 months) with DLDs in special education classrooms during preschool and in kindergarten. Teacher–child relationship quality was assessed in preschool, and children's classroom‐learning behaviours were measured in preschool and kindergarten. Regression models were used to examine the relationship between teacher–child relationship quality and children's concurrent and future classroom‐learning behaviours. Outcomes & Results: Positive teacher–child relationship quality in preschool was associated with better classroom‐learning behaviours in preschool and kindergarten for children with DLDs. Preschool teacher–child relationship quality characterized by low levels of conflict and high levels of closeness was associated with positive classroom‐learning behaviours during preschool. Teacher–child conflict but not closeness was predictive of children's classroom‐learning behaviours in kindergarten. Conclusions & Implications: These results suggest that the quality of the teacher–child relationship for children with DLDs during preschool is associated within their learning‐related behaviours in the classroom both concurrently and in the subsequent year. Findings suggest that teacher–child relationships should be explored as a mechanism for improving the learning‐related behaviours of children with DLDs. [ABSTRACT FROM AUTHOR]

To contribute to the modest body of work examining the home literacy environment (HLE) and emergent literacy outcomes for children with disabilities, this study addressed two aims: (a) to determine the unique contributions of the HLE on print knowledge of preschool children with language impairment and (b) to identify whether specific child characteristics (oral language ability, print interest) moderated these relations. The sample consisted of 119 preschool children with language impairment. HLE was conceptualised as frequency of storybook reading and literacy teaching during book reading. Frequency of storybook reading was a unique predictor of print knowledge, which is consistent with research on children with typical language. Literacy teaching did not predict print knowledge, which diverges from research on children with typical language. No interactions between the HLE and child characteristics were significant, but language ability and print interest play a role in understanding individual differences in literacy development. [ABSTRACT FROM AUTHOR]

The third of this three-part series on water-related sports dermatoses discusses skin changes seen in athletes who participate in sporting activities on top of or nearby water. While also susceptible to several of the freshwater and saltwater dermatoses discussed in parts one and two of the series, these athletes may present with skin changes unique to their particular sports. This updated and comprehensive review details those near-water dermatologic conditions commonly seen in sailors, rowers, fishermen, surfers, windsurfers, rafters, and water skiers, and will serve as a guide for dermatologists, sports medicine physicians and other medical practitioners in recognition and treatment of these conditions. [ABSTRACT FROM AUTHOR]

The second part of this three-part series on water-related dermatoses will discuss dermatologic conditions seen in athletes exposed to saltwater. The vast majority of the following dermatoses result from contact with organisms that inhabit saltwater, including bacteria, cnidarians, and echinoderms. This review also will include other dermatoses affecting saltwater athletes and should serve as a guide for dermatologists, sports medicine physicians, and other medical practitioners in recognition and treatment of these dermatoses. [ABSTRACT FROM AUTHOR]

The first of this three-part series on water-related dermatoses involving the athlete will include sports occurring with the majority of time spent in the water. These sports include swimming, diving, scuba, snorkeling and water polo. Numerous authors have described dermatologic conditions commonly seen in swimmers. This series provides an updated and comprehensive review of these water dermatoses. In order to organize the vast number of skin conditions related to water exposure, we divided the skin conditions into groupings of infectious and organism-related dermatoses, irritant and allergic dermatoses and miscellaneous dermatoses. The vast majority of skin conditions involving the water athlete result from chemicals and microbes inhabiting each environment. When considering the effects of swimming on one’s skin, it is also useful to differentiate between exposure to freshwater (lakes, ponds and swimming pools) and exposure to saltwater. This review will serve as a guide for dermatologists, sports medicine physicians and other medical practitioners in recognition and treatment of these conditions. [ABSTRACT FROM AUTHOR]

A growing body of literature has identified the association between neutrophilic dermatoses and multifocal, aseptic bone lesions in children, termed chronic recurrent multifocal osteomyelitis (CRMO). Classically, patients present with swelling, pain, and impaired mobility of the affected area, with skin lesions developing concurrently or in the future. Bone biopsy reveals inflammatory changes consistent with infectious osteomyelitis, but cultures and histologic staining invariably fail to identify an infectious source. Patients are refractory to antibiotic therapy, but dramatically respond to systemic steroids and may need to be maintained on low-dose steroids to prevent relapse. Numerous authors have suggested that CRMO and synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome lie along the same clinical spectrum. In fact some believe that CRMO is the pediatric presentation of SAPHO. The two syndromes share numerous characteristics, including osteitis, a unifocal or multifocal presentation, hyperostosis, and pustulosis, which all occur in a generally healthy individual. Our seven patients, five of whom were diagnosed with CRMO, and two of whom were diagnosed with SAPHO syndrome further strengthen the idea that CRMO and SAPHO syndrome do indeed lie along the same clinical spectrum. In addition, we include two rare cases of pediatric Sweet’s syndrome with evidence of pathergy. [ABSTRACT FROM AUTHOR]

Ice core records show atmospheric methane mixing ratio and interpolar gradient varying with climate. Changes in wetland sources have been implicated as the basis for this observed variation in the record, but more recently, modeling studies suggest that changes in the CH4 sink resulting from changes in sea surface temperature (SST) and emissions of other volatile organic carbon (VOC) compounds by vegetation must also be considered. We use the Goddard Institute for Space Studies (GISS) General Circulation Model (GCM) with the GISS Tropospheric Chemistry Model to study the response of the methane mixing ratio to source changes during the Holocene and also to a changing chemical sink during glacial-interglacial transitions. We combine model results with ice core data to demonstrate a method that provides constraints on changes in northern and tropical methane sources. Results show that within the Holocene, changes in the atmospheric methane mixing ratio and latitudinal gradient are not linear with respect to changing methane emissions. Tropical and northern emissions varied from preindustrial levels by as much as 38% and 15%, respectively, within the Holocene. At glacial-interglacial transitions the methane mixing ratio is sensitive to changes in both VOC and tropical methane emissions and the sensitivity also depends strongly on the assumed SST shift. Our findings suggest that changes in the ice core methane record are likely the result of changes in both the source and the sink. Changes in the sink become especially important when changes in methane mixing ratio and/or climate are large. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented discussing the case of a 72-year-old man with postoperative pathergic pyoderma gangrenosum following aortic aneurysm repair.

The article presents a case study of a 40-year-old Chinese with hepatocellular carcinoma (HCC) and was experiencing three months of mid-back pain and two enlarging facial nodules. The punch biopsy conducted for the facial nodules of the patient revealed nodular aggregates of atypical epithelial cells associated with increase in number of blood vessels. It discusses HHC which is considered to be a rare cause of cutaneous metastasis, adding that most metastatic lesions occur in the lungs.

Sporotrichosis is caused by the dimorphic fungus, Sporothrix schenckii. Classically, infection occurs after implantation of the organism into the skin by abrasion of a puncture wound by contaminated thorns, hay, or sphagnum moss. Cats are also a commonly recognized source of sporotrichosis. In children, fixed cutaneous lesions are more common than lymphocutaneous lesions, and the face is a frequent location for infection. We present a neonate with a fixed cutaneous facial lesion and both pre-auricular and cervical lymphadenopathy who developed signs of infection at 3 weeks of age. This patient is currently the youngest reported case of sporotrichosis in the literature. The patient’s family denied any trauma and denied contact with flowers, gardens, and cats; thus, the source of infection remains unknown. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) is a strong greenhouse gas whose mole fraction in the atmosphere has increased over the industrial period. We present a new set of isotope measurements of N2O in air extracted from ice cores covering the last 3,000 years. For the preindustrial (PI) atmosphere, we find an average N2O mole fraction of (267 ± 1) nmol/mol and average tropospheric N2O isotopic values of δ15NavPI = (9.5 ± 0.1)‰, δ18OPI = (47.1 ± 0.2)‰, δ15NαPI = (17.8 ± 0.4)‰, and δ15ΝβPI = (1.2 ± 0.4)‰. From PI to modern times all isotope signatures decreased with a total change of δ15Nav = (−2.7 ± 0.2)‰, δ18O = (−2.5 ± 0.4)‰, δ15Nα = (−2.0 ± 0.7)‰, and δ15Νβ (−3.5 ± 0.7)‰. Interestingly, the temporal evolution is not the same for δ15Nav and δ18O. δ18O trends are relatively larger during the early part, and δ15Nav trends are larger during the late part of the industrial period, implying a decoupling of sources over the industrial period. Using a mass balance model, we determined the isotopic composition of the total average N2O source. Assuming that the total present source is the sum of a constant natural source and an increasing anthropogenic source, this anthropogenic source has an isotopic signature of δ15Navsource,anthrop = (−15.0 ± 2.6)‰, δ18Osource,anthrop = (30.0 ± 2.6)‰, δ15Nαsource,anthrop = (−4.5 ± 1.7)‰, and δ15Nβsource,anthrop = (−24.0 ± 8.4)‰. The 15N site preference of the source has increased since PI times, which is indicative of a relative shift from denitrification to nitrification sources, consistent with agricultural emissions playing a major role in the N2O increase. Key Points: The isotopic composition of nitrous oxide in the preindustrial period was determined with high precisionThe isotopic composition of nitrous oxide changed during the transition to the industrial periodThe temporal evolution of δ15Nav is different from that of δ18O implying a decoupling of sources over the industrial period [ABSTRACT FROM AUTHOR]

A letter to the editor about the case of a 54-year-old Caucasian female patient with a bilateral axillary eruption and follicular papules, which were consitent with the diagnosis of crystal deodorant-induced axillary granulomatous dermatitis is presented.

The structures of three fluoro-substituted acetoacetanilides, namely 2'-, 3'- and 4'-fluoroacetoacetanilide, all C(10)H(10)FNO(2), are presented and discussed. We observe a planar structure with intramolecular hydrogen bonding when the F atom is in the ortho position of the aromatic ring, and a twisted structure with intermolecular hydrogen bonding when the F atom is in the meta or para positions. It can be predicted which of these two structural motifs will be adopted by considering the position of any aromatic substituents. In this regard, fluorine appears to mimic the steric effect of a larger substituent, which we attribute to its high electronegativity.