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The article focuses on the multigenerational workforce, which requires disability management specialist, and safety health and environment professionals (SH&E) to be creative in activity planning and preventing illness and injuries. It states that multigenerational workplace can promote institutional knowledge, adaptability, and new ideas despite demographic group categories. It adds that safety and health are common denominators that affect workers regardless of generational differences.

Abstract: Saccharomyces cerevisiae leukotriene A4 hydrolase (LTA4H) is a bifunctional aminopeptidase/epoxide hydrolase and a member of the M1 family of metallopeptidases. In order to obtain a more thorough understanding of the aminopeptidase activity of the enzyme, two conserved tyrosine residues, Tyr244 and Tyr456, were altered to phenylalanine and the mutant proteins characterized by determining K M and k cat for various amino acid β-naphthylamide substrates. While mutation of Tyr456 exhibited minimal effect on catalysis, mutation of Tyr244 caused an overall 25–100-fold reduction in catalytic activity for all substrates tested. Furthermore, LTA4H Y244F exhibited a 40-fold decrease in affinity for RB-3014, a transition state analog inhibitor, implicating Tyr244 in transition state stabilization. [Copyright &y& Elsevier]

Laser Doppler anemometry (LDA) with burst spectrum analysis (BSA) is used to study the acoustic streaming generated in a cylindrical standing-wave resonator filled with air. The air column is driven sinusoidally at a frequency of approximately 310 Hz and the resultant acoustic-velocity amplitudes are less than 1.3 m/s at the velocity antinodes. The axial component of fluid velocity is measured along the resonator axis, across the diameter, and as a function of acoustic amplitude. The velocity signals are postprocessed using the Fourier averaging method [Sonnenberger et al., Exp. Fluids 28, 217–224 (2000)]. Equations are derived for determining the uncertainties in the resultant Fourier coefficients. The time-averaged velocity-signal components are seen to be contaminated by significant errors due to the LDA/BSA system. In order to avoid these errors, the Lagrangian streaming velocities are determined using the time-harmonic signal components and the arrival times of the velocity samples. The observed Lagrangian streaming velocities are consistent with Rott’s theory [N. Rott, Z. Angew. Math. Phys. 25, 417–421 (1974)], indicating that the dependence of viscosity on temperature is important. The onset of streaming is observed to occur within approximately 5 s after switching on the acoustic field. © 2005 Acoustical Society of America. [ABSTRACT FROM AUTHOR]

Following the experimental method of Thompson and Atchley [J. Acoust. Soc. Am. 117, 1828–1838 (2005)] laser Doppler anemometry (LDA) is used to investigate the influences of a thermoacoustically induced axial temperature gradient and of fluid inertia on the acoustic streaming generated in a cylindrical standing-wave resonator filled with air driven sinusoidally at a frequency of 308 Hz. The axial component of Lagrangian streaming velocity is measured along the resonator axis and across the diameter at acoustic-velocity amplitudes of 2.7, 4.3, 6.1, and 8.6 m/s at the velocity antinodes. The magnitude of the axial temperature gradient along the resonator wall is varied between approximately 0 and 8 K/m by repeating measurements with the resonator either surrounded by a water jacket, suspended within an air-filled tank, or wrapped in foam insulation. A significant correlation is observed between the temperature gradient and the behavior of the streaming: as the magnitude of the temperature gradient increases, the magnitude of the streaming decreases and the shape of the streaming cell becomes increasingly distorted. The observed steady-state streaming velocities are not in agreement with any available theory. © 2005 Acoustical Society of America. [ABSTRACT FROM AUTHOR]

The puromycin-sensitive aminopeptidase (ApPS) is a zinc metallopeptidase involved in the degradation of neuropeptides. Putative catalytic residues of the enzyme, Cys146, Glu338, and Lys396 were mutated, and the resultant mutant enzymes characterized. ApPS C146S exhibited normal catalytic activity, ApPS E338A exhibited decreased substrate binding, and ApPS K396I exhibited decreases in both substrate binding and catalysis. ApPS K396I and ApPS Y394F were analyzed with respect to transition state inhibitor binding. No effect was seen with the K396I mutation, but ApPS Y394F exhibited a 3.3-fold lower affinity for RB-3014, a transition state inhibitor, indicating that Tyr394 is involved in transition state stabilization. [Copyright &y& Elsevier]

The active site glutamate, Glu 309, of the puromycin-sensitive aminopeptidase was mutated to glutamine, alanine, and valine. These mutants were characterized with amino acid β-naphthylamides as substrates and dynorphin A(1-9) as an alternate substrate inhibitor. Conversion of glutamate 309 to glutamine resulted in a 5000- to 15,000-fold reduction in catalytic activity. Conversion of this residue to alanine caused a 25,000- to 100,000-fold decrease in activity, while the glutamate to valine mutation was the most dramatic, reducing catalytic activity 300,000- to 500,000-fold. In contrast to the dramatic effect on catalysis, all three mutations produced relatively small (1.5- to 4-fold) effects on substrate binding affinity. Mutation of a conserved tyrosine, Y394, to phenylalanine resulted in a 1000-fold decrease in kcat, with little effect on binding. Direct binding of a physiological peptide, dynorphin A(1-9), to the E309V mutant was demonstrated by gel filtration chromatography. Taken together, these data provide a quantitative assessment of the effect of mutating the catalytic glutamate, show that mutation of this residue converts the enzyme into an inactive binding protein, and constitute evidence that this residue acts a general acid/base catalyst. The effect of mutating tyrosine 394 is consistent with involvement of this residue in transition state stabilization. [Copyright &y& Elsevier]

The article reports on the expanding commitment of the American Society of Safety Engineers (ASSE) to grow the society in the context of a global profession. It relates that ASSE members have pursued many possibilities in fiscal year 2008, achieved many of their goals, and they are individually and collectively learned and progressed. The ASSE's ability to help members succeed is reflecting in their growth trend in fiscal year 2008, during which membership increased 2.8% to reach 32, 211 members. Moreover, it cites the effort of the ASSE members to advance its practitioners through technical excellence, social responsibility and safety, health and environmental excellence on their workplaces and communities.

A letter to President George W. Bush concerning the reappointment of NIOSH director John Howard is presented.

The author offers his views on how the American Society of Safety Engineers (ASSE) has responded to the evolving global responsibilities of its membership. The organization's purpose, vision mission statements, and corresponding strategic goals have changed. Members have seen opportunities to become a global champion of the safety, health and environmental (SH&E) professional. ASSE has invested resources in advocacy work and has reached out to many important stakeholders.

The author reflects on the development of the North American Occupational Safety and Health (NAOSH) Week celebration. He states that the event serves as an international stage to show the essence of safety performance in businesses, as well as an incident-free workplace with lower healthcare costs. He adds that the NAOSH Week will also offer individuals the chance to make difference in the personal area of influence through local engagement.

The author reflects on the issues concerning the American Society of Safety Engineers (ASSE) election in 2008. He mentions about the importance of the participation of the members on the results of the election. Furthermore, he stresses that by not voting, members shift accountability to others to determine the future direction of the organization. He also believes that the set of candidates in this year's election have impressive credentials.

The author reflects on the importance of adopting technology applications in addressing work expectations for safety, health and environment professionals. He states that several companies are now using Web 2.0 applications in order for them to respond faster in the increasing expectations of excellence. He believes that technology will help professionals in achieving virtual knowledge sharing and global connectivity which will unite geography and organizations.

The article discusses the vision and mission of the American Society of Safety Engineers (ASSE) in the U.S. Since it cannot achieve its goal without the cooperation of the members, ASSE increases its membership by 3% yearly and continually develops its nondues initiatives through conferences, symposia, webinars, books, standards, journal advertising and training. The author stresses that the organization's finances and spending should be balanced by income so that revenue ratio will continue to be an important aspect of the group's operation. The dues paid by members are used in an efficient matter wherein it helps ASSE in promoting the profession in a significant and accurate way and helps the organization in promoting better career and professional opportunities among members.

The article focuses on the author's perspective on the strategic goals set by the American Society of Safety Engineers (ASSE) which are crucial to the profession's future in the U.S. He said that ASSE and each of its members and the professionals committed in the safety, health and environment (SH&E) must find ways to pay it forward for their profession and for the students. He stated that these students will have a chance to interact, network and share with seasoned professionals, with the goal of guiding their transition from students to practitioners to professionals and eventually, to Society leaders.

The author reflects on the views from the senior executives in understanding the business enterprises. The author said that executives wanted to provide metrics that can project benefits and savings from Safety, Health and Environmental (SH&E) management systems. Moreover, he admits that the activity demonstrate the key role of members in helping the success of the business enterprises.

The author discusses the vision and mission of the American Society of Safety Engineers as presented during the annual Professional Development Conference and Exposition in Orlando, Florida. He states that the conference was attended by nearly 35 countries to take hold of the opportunities to share their experiences including the exchanging of views and sharpens their safety, health and evironmental and business skills. He adds that the society focuses on the members and its customers including those individuals who make business decisions. He also presented the book entitled "Execution" by Larry Bossidy which talks about customers who have fixed demand for products.

The article presents a message from the president of the American Society of Safety Engineers, a Des Plaines, Illinois-based professional safety organization that works to develop the technical, scientific, managerial and ethical knowledge and skills of occupational safety. The presidents stressed that the profession encounter many challenges in the present due to the changes that are inevitable in the society. He said that many factors are influencing the safety health and environmental performance including the changing geopolitical relationships and redistribution of businesses. The president conveyed to the members of the organization to recognize the fact that affects the profession and the membership, now and in the future.

Phoresy is a behaviour where one organism hitches a ride on another more mobile organism. This is a common dispersal mechanism amongst relatively immobile species that specialise on patchy resources. Parasites specialise on patchily distributed resources: their hosts. Although host individuals are isolated in space and time, parasites must transmit between hosts or they will die with their hosts. Lice are permanent obligate ectoparasites that complete their entire life cycle on their host. They typically transmit when hosts come into direct contact; however, lice are also capable of transmitting phoretically. Yet, phoresy is rare amongst some groups of lice. Fundamental morphological differences have traditionally been used to explain the phoretic differences amongst different suborders of lice; however, these hypotheses do not fully explain observed patterns. We propose that a more fundamental natural history trait may better explain variation in phoresy. Species able to disperse under their own power should be less likely to engage in phoresy than more immobile species. Here we experimentally tested the relationship between independent louse mobility and phoresy using a system with four species of lice (Phthiraptera: Ischnocera and Amblycera) that all parasitize a single host species, the Rock Pigeon ( Columba livia ). We quantified the relative ability of all four species of lice to move independently off the host, and we quantified their ability to attach to, and remain attached to, hippoboscid flies ( Pseudolynchia canariensis ). Our results show that the most mobile louse species is the least phoretic, and the most phoretic species is quite immobile off the host. Our findings were consistent with the hypothesis that phoretic dispersal should be rare amongst species of lice that are capable of independent dispersal; however other factors such as interspecific competition may also play a role. [ABSTRACT FROM AUTHOR]

Abstract: Zinc metallopeptidases are ubiquitous enzymes with diverse cellular functions that can be found in most organisms. Leukotriene A4 hydrolase (LTA4H; E.C. 3.3.2.6) is an unusual zinc metallopeptidase of the M1 family that also possesses an epoxide hydrolase activity; however, the role of its peptidase activity remains unknown. To further characterize the peptidase activity of LTA4H and other closely related metallopeptidases, a multiple sequence alignment and predicted structure were used to target three amino acid residues of yeast LTA4H for mutagenesis: Asn362, Trp365, and Asp399. Although mutating Trp365 and Asp399 had little effect on catalysis, altering Asn362 had varying effects on catalysis, depending on the replacement residue. Mutation of Asn362 to glutamine (N362Q) caused minor catalytic defects, while mutation to leucine (N362L) or glutamate (N362E) caused large reductions in activity. Both N362L and N362E also exhibited an altered pH dependence of catalysis, reduced chloride activation, and reduced zinc affinity and content, indicating that Asn362 may interact with the nearby zinc coordinating residue His344, and possibly with Glu363 as well, to polarize and/or orient these residues. [ABSTRACT FROM AUTHOR]

Streptokinase (SK) conformationally activates the central zymogen of the fibrinolytic system, plasminogen (Pg). The SK∙Pg* catalytic complex binds Pg as a specific substrate and cleaves it into plasmin (Pm), which binds SK to form the SKPm complex that propagates Pm generation. Catalytic complex formation is dependent on lysine-binding site (LBS) interactions between a Pg/Pm kringle and the SK COOH-terminal Lys414. Pg substrate recognition is also LBS-dependent, but the kringle and SK structural element(s) responsible have not been identified. SK mutants lacking Lys414 with Ala substitutions of charged residues in the SK 13-domain 250-loop were evaluated in kinetic studies that resolved conformational and proteolytic Pg activation. Activation of [Lys]Pg and mini-Pg (containing only kringle 5 of Pg) by SK with Ala substitutions of Arg253, Lys256, and Lys257 showed decreases in the bimolecular rate constant for Pm generation, with nearly total inhibition for the SK Lys256/Lys257 double mutant. Binding of bovine Pg (BPg) to the SKPm complex containing fluorescently labeled Pm demonstrated LBS-dependent assembly of a SKlabeled PmBPg ternary complex, whereas BPg did not bind to the complex containing the SK Lys256/Lys257 mutant. BPg was activated by SKPm with a Km indistinguishable from the KD for BPg binding to form the ternary complex, whereas the SK Lys256/Lys257 mutant did not support BPg activation. We conclude that SK residues Arg253, Lys256, and Lys257 mediate Pg substrate recognition through kringle 5 of the [Lys]Pg and mini-Pg substrates. A molecular model of the SKkringle 5, complex identifies the putative interactions involved in LBS-dependent Pg substrate recognition. [ABSTRACT FROM AUTHOR]

Lactoferrin (LTF) is a multifunctional iron-binding protein that is also capable of binding other divalent metal cations, especially Zn2+. Recent investigations indicate that lactoferrin levels are elevated in many disease conditions in which matrix metalloproteinases (MMPs), particularly MMP-2, are also elevated, suggesting that the 2 proteins may interact. This possibility was examined by determining the effect of LTF in its holo (metal-bound) and apo (metal-free) forms on the proteolytic activity of MMP-2 and other similar zinc metalloproteases. Pre-incubation with apolactoferrin, but not hololactoferrin, greatly reduced the hydrolysis of a peptide substrate by MMP-2, but not by MMP-1, -8, -9, or -13. This inhibition was specific for the 42 kDa catalytic domain fragment of MMP-2 lacking the hemopexin domain, since the 66 kDa form was poorly inhibited by apolactoferrin. The inhibition of the MMP-2 catalytic domain was strongly temperature sensitive, indicating that the conformation of one or both proteins is crucial to this interaction. To ascertain the mechanism of inhibition, increasing concentrations of ZnCl2 and FeCl2 were added to the reaction. While addition of Fe2+ did not reverse inhibition, the addition of Zn2+ resulted in a recovery of MMP-2 activity, and furthermore, zinc-saturated LTF did not inhibit MMP-2. Together, these data strongly suggest that apolactoferrin is capable of removing the catalytic zinc from the active site of MMP-2, although an exosite-based interaction between the 2 proteins cannot be fully ruled out. This inhibitory activity suggests a novel function for LTF and may represent a novel regulatory mechanism that regulates proteolysis by MMP-2 in vivo. [ABSTRACT FROM AUTHOR]

The puromycin-sensitive aminopeptidase was found to be resistant to proteolysis by trypsin, chymotrypsin, and protease V8 but was cleaved into an N-terminal 60-kDa fragment and a C-terminal 33-kDa fragment by proteinase K. The two proteinase K fragments remain associated and retained enzymatic activity. Attempts to express the 60-kDa N-terminal fragment in Escherichia coli produced inclusion bodies. A hexa-histidine fusion protein of the 60-kDa N-terminal fragment was solubilized from inclusion bodies with urea and refolded by removal of the urea through dialysis. The refolded protein was devoid of aminopeptidase activity as assayed with arginine–β-naphthylamide. However, the refolded protein bound the substrate dynorphin A(1-9) with a stoichiometry of 0.5 mol/mol and a K0.5 value of 50 μM. Dynorphin A(1-9) binding was competitively inhibited by the substrate dynorphin B(1-9), but not by des-Tyr1-leucine-enkephalin, a poor substrate for the enzyme. [Copyright &y& Elsevier]

The proteasome generates exact major histocompatibility complex (MHC) class I ligands as well as NH2-terminal-extended precursor peptides. The proteases responsible for the final NH2-terminal trimming of the precursor peptides had, until now, not been determined. By using specific selective criteria we purified two cytosolic proteolytic activities, puromycin-sensitive aminopeptidase and bleomycin hydrolase. These proteases could remove NH2-terminal amino acids from the vesicular stomatitis virus nucleoprotein cytotoxic T cell epitope 52?59 (RGYVYQGL) resulting, in combination with proteasomes, in the generation of the correct epitope. Our data provide evidence for the existence of redundant systems acting downstream of the proteasome in the antigen-processing pathway for MHC class I molecules. [ABSTRACT FROM AUTHOR]