FOREST ECOLOGY. Pervasive drought legacies in forest ecosystems and their implications for carbon cycle models.

The impacts of climate extremes on terrestrial ecosystems are poorly understood but important for predicting carbon cycle feedbacks to climate change. Coupled climate-carbon cycle models typically assume that vegetation recovery from extreme drought is immediate and complete, which conflicts with the understanding of basic plant physiology. We examined the recovery of stem growth in trees after severe drought at 1338 forest sites across the globe, comprising 49,339 site-years, and compared the results with simulated recovery in climate-vegetation models. We found pervasive and substantial "legacy effects" of reduced growth and incomplete recovery for 1 to 4 years after severe drought. Legacy effects were most prevalent in dry ecosystems, among Pinaceae, and among species with low hydraulic safety margins. In contrast, limited or no legacy effects after drought were simulated by current climate-vegetation models. Our results highlight hysteresis in ecosystem-level carbon cycling and delayed recovery from climate extremes.

Salmonella collected from nest run cart shelves in commercial shell egg processing facilities.

Salmonella, a member of the bacterial family Enterobacteriaceae, may be recovered from foods and processing facilities. High levels of Enterobacteriaceae in the processing plant environment can be an indication of inadequate sanitation. This experiment was designed to determine if nest run egg carts serve as reservoirs for Salmonella. Eggs that are produced by hens not housed in buildings connected to the processing plant are referred to as nest run. Many of these eggs are transported to a central processing facility before they are washed, graded, and packed. Two plants in the Southeastern United States were sampled; one was a mixed operation and the other was an off-line operation. On each of 3 visits, 5 shelves on each of 5 carts were sampled (n = 25/visit). A 12 × 12 cm area on each shelf was swabbed with a sterile gauze pad moistened with PBS and transported on ice back to the laboratory. Each swab was preenriched in buffered peptone at 37°C for 24 h, selectively enriched using TT and Rappaport-Vassiliadis broth at 42°C overnight, then plated onto brilliant green sulfa and XLT-4 incubated at 37°C for 24 h. Presumptive colonies were transferred to lysine iron agar and triple sugar iron slants for 24 h at 37°C. Isolates with presumptive reactions were confirmed using commercial polyclonal antisera. After initial confirmation, serogrouping was performed using commercial antisera. Mixed-operation swab samples were 12% positive for Salmonella, whereas off-line samples were 36% positive for Salmonella; isolates were confirmed as serogroups B, C1, and C2. Kauffman-White serotyping was performed by a contract laboratory. Serotypes (n = 30) recovered were Anatum, Heidelberg, Infantis, Kentucky, Mbandanka, and Typhimurium. This work demonstrated that nest run egg carts may serve as reservoirs for Salmonella in the shell egg processing environment.

Enterobacteriaceae and related organisms isolated from nest run cart shelves in commercial shell egg processing facilities.

Enterobacteriaceae, including Salmonella, may be recovered from foods and processing facilities. High levels of Enterobacteriaceae in the processing plant environment can be an indication of inadequate sanitation. This experiment was designed to determine if nest run egg carts serve as reservoirs for Enterobacteriaceae. Eggs that are produced by hens not housed in buildings connected to the processing plant are referred to as nest run. Many of these eggs are transported to the plant on carts to be processed. Two plants in the southeastern United States were sampled. On each of 3 visits, 5 shelves on each of 5 carts were sampled (n=25/visit). A 12x12 cm area on each shelf was swabbed with a sterile gauze pad moistened with PBS and transported on ice back to the laboratory. Enterobacteriaceae were enumerated using violet red bile glucose agar incubated at 37 degrees C for 24 h. There was 100% prevalence for Enterobacteriaceae at plant A with an average 3.8 log10 cfu/mL swab diluent. Plant B had 90% prevalence for Enterobacteriaceae with an average 3.2 log10 cfu/mL swab diluent. Two randomly selected isolates from each positive sample were recultured 3 times to increase the likelihood of clonality and were then identified biochemically. Of the 124 isolates analyzed, genera identified were Citrobacter spp., Escherichia spp., Enterobacter spp., Klebsiella spp., Hafnia spp., Kluyvera spp., Leclercia spp., and Salmonella spp. Pseudomonas spp. was the only non-Enterobacteriaceae identified by our methods. This work demonstrates that nest run egg carts serve as reservoirs for Enterobacteriaceae in the shell egg processing environment.

Fluorescent labeling of yeast.

This unit describes the use of several different fluorescence methods for labeling yeast cells. It includes methods to label the vacuole, the actin cytoskeleton, and chitin deposits on cell walls (bud scars), as well as methods for visualizing specific proteins in live cells with GFP chimeras and in fixed cells by immunofluorescence.

Yeast as a model system for studying endocytosis.

Endocytosis is the membrane trafficking process by which plasma membrane components and extracellular material are internalized into cytoplasmic vesicles and delivered to early and late endosomes, eventually either recycling back to the plasma membrane or arriving at the lysosome/vacuole. The budding yeast Saccharomyces cerevisiae has proven to be an invaluable system for identifying proteins involved in endocytosis and elucidating the mechanisms underlying internalization and postinternalization events. Through genetic studies in yeast and biochemical studies in mammalian cells, it has become apparent that multiple cellular processes are linked to endocytosis, including actin cytoskeletal dynamics, ubiquitylation, lipid modification, and signal transduction. In this review, we will highlight the most exciting recent findings in the field of yeast endocytosis. Specifically, we will address the involvement of the actin cytoskeleton in internalization, the role of ubiquitylation as a regulator of multiple steps of endocytosis in yeast, and the sorting of endocytosed proteins into the recycling and vacuolar pathways.

Personality moderators of the relationship between abusive supervision and subordinates' resistance.

Results of a study using data collected at 2 points in time, separated by 6 months, suggested that subordinates resisted their supervisors' downward influence tactics with greater frequency when their supervisors were more abusive and that subordinates' personality moderated the effects of abusive supervision. The relationship between abusive supervision and subordinates' dysfunctional resistance was stronger among subordinates who were lower in conscientiousness than among subordinates who were higher in conscientiousness, but this effect emerged only for subordinates who were also lower in agreeableness. The relationship between abusive supervision and subordinates' constructive resistance was stronger among subordinates who were higher in conscientiousness than among subordinates who were lower in conscientiousness. The study's implications for theory and research are discussed.

Positive affectivity and negative outcomes: the role of tenure and job satisfaction.

In this study, the authors proposed and tested a 3-way interaction among positive affectivity (PA), job satisfaction, and tenure in predicting negative employee outcomes. Specifically, the authors predicted that the relationship between job satisfaction and negative outcomes would be stronger for high PAs and that this relationship would be more pronounced for longer tenured employees. Results support this 3-way interaction in predicting job search behavior, physical health complaints, and counterproductive employee behavior. In particular, the relationship between job satisfaction and negative outcomes was most strongly negative for high-PA individuals with longer tenure. The authors discuss the implications of these results and some directions for future research.

A retrospective analysis of the results of 218 consecutive rhinoplasties.

In a 7-year period, 218 consecutive rhinoplasties were performed within a joint rhinoplasty service comprising a plastic surgeon and an otorhinolaryngologist. Retrospective analysis of these procedures revealed a minor surgical complication rate of 5%, no major complications and requests for revisional surgery in 10% of patients after primary rhinoplasty by the service. However when patients had not had their first operation by our joint service, the revisional operation rate after our first operation was 19%. These results are discussed in relation to other published series. The data generated should enable more precise preoperative patient counselling and act as a useful baseline for subsequent audit of performance. Specifically, patients should know that after rhinoplasty 1 in 10 patients may request revisional surgery. All trainers and trainees should be aware of such data on their own patients in order that standards be set and enhanced with time.

Kikuchi's necrotising lymphadenitis.

Three cases of Kikuchi's necrotizing lymphadenitis without granulocytic infiltration presented to the ENT department as cervical lymphadenopathy with neutropaenia. Differential diagnosis from malignant lymphoma was difficult both clinically and histopathologically. Two recovered spontaneously without treatment within three months, one improved initially but was lost to follow-up after one month.

Shapes of benz[a]anthracenes: the crystal and molecular structure of 6-methylbenz[a]anthracene.

The crystal structure of 6-methylbenz[a]anthracene (6-MBA), a more potent carcinogen than the other K-region monomethyl-substituted benz[a]anthracene (5-MBA), has been determined by application of direct methods to single-crystal X-ray diffractometric data and refined by least squares to R = 0.047 (Rw = 0.053). Deviations of the carbon atoms from planarity are very small with even the methyl carbon displaced by only 0.05 A from the mean molecular plane. The benzo-ring A is inclined at only about 1 1/2 degrees to each of the three rings in the anthracene moiety, i.e. 6-MBA is one of the most nearly planar benz[a]anthracenes. The K-region bond C(5)-C(6) = 1.328(6) A and two other short bonds are C(8)-C(9) = 1.341(7) and C(10)-C(11) = 1.361(7) A in the anthracene D ring.

Steric strain and tumorigenicity: the molecular structure of 3,6-dimethylcholanthrene.

The crystal structure of 3,6-dimethylcholanthrene, a highly tumorogenic polycyclic aromatic hydrocarbon, has been solved and refined, from X-ray diffractometric data collected at room temperature, to an R index 0.050 over 1684 independent reflections. The steric strain arising from the presence of the bay-methyl substituent distorts the molecule almost as much as in the moderately carcinogenic 1- and 12-methylbenz[a]anthracenes, with the benzo A ring inclined at approximately 16 degrees to the furthest C and D rings. The 6-methyl carbon atom is displaced 0.7 A from the molecular plane and the beach bond length of the bay region is 1.480(6) A, with beach C-C-C angles of 124.1 and 123.5 degrees. The shortest carbon-carbon bond is C(5)-C(6) = 1.331(7) A at the K region, with the next shortest C(8)-C(9) = 1.362(7), C(10)-C(11) = 1.366(7), and C(3)-C(4) = 1.369(8) A.

Rhabdomyosarcoma of the nasopharynx a case with recurrence of tumour after 20 years.

A case of embryonal (botryoid) rhabdomyosarcoma of the nasopharynx originally occurring in a two year old male, with late recurrence in the neck 20 years after treatment by combined surgery and radiotherapy is presented. The histological diagnosis of rhabdomyosarcoma, and the significance of late recurrence are discussed.

X-ray refinement of the crystal and molecular structure of 1,12-dimethylbenz[a]anthracene.

The molecular and crystal structure of 1,12-dimethylbenz[a]anthracene, one of the least carcinogenic of the benz[a]anthracenes, has been refined, from new X-ray diffractometric data collected at room temperature, to an R index 0.047 over 1217 independent reflections. Improved determination of molecular geometry shows that steric strain arising from the presence of two bay-methyl substituents causes even greater molecular distortion than in the highly carcinogenic 7,12-dimethylbenz[a]anthracene, with the benzo A ring inclined at about 29 degrees to the furthest C and D rings. Methyl carbon atoms are displaced 1.0 and 1.3 A on opposite sides of the mean molecular plane and the beach bond of the bay region is 1.480(4) A long, flanked by C-C-C angles of 124.3 and 125.0 degrees. The shortest carbon-carbon bond is C5-C6 = 1.327(5) A at the K region, with the next shortest C8-C9 = 1.346(6) A. Close intramolecular approaches of methyl hydrogens across the bay and to nearest aromatic hydrogens are 2.3-2.6 A.