Search

Observations of fish behavior can provide insights into habitat preferences and use. Black sea bass, Centropristis striata, are a territorial temperate reef finfish species known for their high commercial and recreational value and association with structured habitat. We used underwater action cameras to record video of black sea bass to assess territorial (agonistic, ambush, displacement) and occupancy (station-keeping) behaviors on shelf and bag style oyster aquaculture cages at a shellfish farm, and on boulders at a natural rock reef near Milford, Connecticut in Long Island Sound, Northwest Atlantic. Black sea bass at a variety of life stages were highly associated with cages, including young-of-the-year, and age 1+ fish. The high abundance of black sea bass observed on cages relative to boulders suggests this species has an affinity for the vertical structure created by aquaculture gear. When behaviors were normalized to the total fish sightings, black sea bass showed no significant difference in frequency of behaviors between habitats, indicating that per-fish rates of behavior were similar on cages and boulders. Demonstration of territorial and occupancy behaviors by black sea bass on, and around cages suggests that aquaculture gear provides structured habitat and ecosystem services for this species similar to natural reefs. These results suggest that essential fish habitat descriptions of manmade structures used by black sea bass could be broadened to include aquaculture gear. Our study provides novel information on behavioral interactions of black sea bass with oyster cages that may support aquaculture permitting and consultation processes. [ABSTRACT FROM AUTHOR]

Macrophages have an important role in the maintenance of tissue homeostasis (1). To perform this function, macrophages must have the capacity to monitor the functional states of their 'client cells': namely, the parenchymal cells in the various tissues in which macrophages reside. Tumours exhibit many features of abnormally developed organs, including tissue architecture and cellular composition (2). Similarly to macrophages in normal tissues and organs, macrophages in tumours (tumour-associated macrophages) perform some key homeostatic functions that allow tumour maintenance and growth (3-5). However, the signals involved in communication between tumours and macrophages are poorly defined. Here we show that lactic acid produced by tumour cells, as a by-product of aerobic or anaerobic glycolysis, has a critical function in signalling, through inducing the expression of vascular endothelial growth factor and the M2-like polarization of tumour-associated macrophages. Furthermore, we demonstrate that this effect of lactic acid is mediated by hypoxia-inducible factor 1α (HIFlα). Finally, we show that the lactate-induced expression of arginase 1 by macrophages has an important role in tumour growth. Collectively, these findings identify a mechanism of communication between macrophages and their client cells, including tumour cells. This communication most probably evolved to promote homeostasis in normal tissues but can also be engaged in tumours to promote their growth., To study tumour-macrophage interactions, we used syngeneic murine tumour models of Lewis lung carcinoma (LLC) and B16-F1 (B16) melanoma cancer cell lines. LLC and B16 cells were subcutaneously injected into [...]

The reaction of arylhalodiazirines with thiophenoxide was studied using the S(RN)1 process. Diphenyl sulfide, benzonitriles, benzamidines and ammonia result from the reaction. The nucleophilic attack of thiophenoxide on the halogen of the halodiazirine does not trigger the process. The facile production of diazirinyl cations and anions cannot be adequately explained by simple concepts related to antiaromaticity and aromaticity.

The dearth of new antibiotics in the face of widespread antimicrobial resistance makes developing innovative strategies for discovering new antibiotics critical for the future management of infectious disease. Understanding the genetics and evolution of antibiotic producers will help guide the discovery and bioengineering of novel antibiotics. We discovered an isolate in Alaskan boreal forest soil that had broad antimicrobial activity. We elucidated the corresponding antimicrobial natural products and sequenced the genome of this isolate, designated Streptomyces sp. 2AW. This strain illustrates the chemical virtuosity typical of the Streptomyces genus, producing cycloheximide as well as two other biosynthetically unrelated antibiotics, neutramycin, and hygromycin A. Combining bioinformatic and chemical analyses, we identified the gene clusters responsible for antibiotic production. Interestingly, 2AW appears dissimilar from other cycloheximide producers in that the gene encoding the polyketide synthase resides on a separate part of the chromosome from the genes responsible for tailoring cycloheximide-specific modifications. This gene arrangement and our phylogenetic analyses of the gene products suggest that 2AW holds an evolutionarily ancestral lineage of the cycloheximide pathway. Our analyses support the hypothesis that the 2AW glutaramide gene cluster is basal to the lineage wherein cycloheximide production diverged from other glutarimide antibiotics. This study illustrates the power of combining modern biochemical and genomic analyses to gain insight into the evolution of antibiotic-producing microorganisms. [ABSTRACT FROM AUTHOR]

Synthesis of substituted alpha-pyrones with chiral appendages involves a cycloaddition between an alpha-oxo-ketene and a ketene. This (4 +2) cycloaddition reaction enables the asymmetric synthesis of 3(S),6(R)-disubstituted alpha-pyrone, a HIV protease inhibitor. Semiempirical AM1 calculations help investigate the mechanism of cycloaddition.

Many modern diagnostic and surgical procedures rely heavily on the use of ionizing radiation. These procedures include computed tomography, nuclear medicine procedures, interventional radiology, and cardiac catheterization and electrophysiology procedures. Recent trends toward increased patient visits and patients with multiple challenging comorbidities have meant that anesthesia providers are increasingly required to provide services in the ancillary areas using ionizing radiation. As a result, anesthesia providers are at a greater-than-ever risk for excessive radiation doses. An overview of some of the basic principles of radiation biology, radiation physics, and radiation protection and specific guidelines related to radiation exposure and pregnancy are described. The effects of radiation exposure are cumulative and permanent, and an understanding of these principles and practices will help anesthesia providers keep their occupational exposure to a minimum. [ABSTRACT FROM AUTHOR]

Ruthenium clusters were reacted with the chelating arene ligand PPh2(CH2)3Ph. First, the phosphorous atom was coordinated to Ru6, Ru5 and Ru3 clusters, and the products of simple addition were fully characterised. A second (and third in the case of Ru3) equivalent of the ligand was then successfully added to the obtained species. Attempts to coordinate the ‘dangling’ benzene ring led to a Ru6 derivative, where a phenyl ring directly bound to the P atom reacted with the cluster, instead of the terminal one. The crystal structures of the compounds [Ru6C(CO)16PPh2(CH2)3Ph] (3), [Ru3(CO)9{PPh2(CH2)3Ph}3] (9), and [Ru6C(CO)13PPh2(CH2)3Ph] (10) were determined by X-ray diffraction. The former two consist of the intact cluster core with either one or three ligands bonded via the P atom, while the latter has additionally one of the phenyl rings on the phosphorous connected to the cluster in a η6 bonding mode. [Copyright &y& Elsevier]

The article discusses the restricted reporting orders in the employment tribunal in Great Britain. Restricted reporting orders were first considered in 1993 as a late amendment to the Trade Union Reform and Employment Rights Bill. Provisions of the Industrial Tribunals Act of 1996 are discussed. Also included are the exercise of discretion by employment tribunals and public policy considerations.

High-frequency chest compressions (HFCC) have been suggested as an alternative to conventional chest physiotherapy to aid sputum clearance in patients with cystic fibrosis (CF). We aimed to compare the active cycle of breathing techniques (ACBT) with the Hayek Oscillator Cuirass, performing HFCC on secretion clearance in children with CF during an exacerbation. Ten children (7 males; median age, 14 years; range, 9-16) received either two supervised sessions using HFCC or two self-treatment ACBT sessions in random order on successive days. Baseline pulmonary function was similar prior to treatments. Sputum weight increased significantly with ACBT compared with HFCC during treatment (5.2 g vs. 1.1 g, P < 0.005, morning; 4.1 g vs. 0.7 g, P < 0.01, afternoon). Pulmonary function improved significantly after morning ACBT (forced vital capacity (FVC): 2.67 l to 2.76 l, P < 0.03; forced expiratory volume in 1 sec (FEV1): 1.59 l to 1.62 l, P < 0.03). Following afternoon ACBT, there was a significant increase in FVC (2.64 to 2.79, P < 0.02), but no significant change in FEV1. Pulmonary function did not change at any time following HFCC. Compared with ACBT, HFCC by Hayek Cuirass is not an effective airway clearance treatment modality for children with CF during an infective exacerbation., (Copyright 2004 Wiley-Liss, Inc.)