Unified Concept of Bottleneck

The term `bottleneck` has been extensively used in operations management literature. Management paradigms like the Theory of Constraints focus on the identification and exploitation of bottlenecks. Yet, we show that the term has not been rigorously defined. We provide a classification of bottleneck definitions available in literature and discuss several myths associated with the concept of bottleneck. The apparent diversity of definitions raises the question whether it is possible to have a single bottleneck definition which has as much applicability in high variety job shops as in mass production environments. The key to the formulation of an unified concept of bottleneck lies in relating the concept of bottleneck to the concept of shadow price of resources. We propose an universally applicable bottleneck definition based on the concept of average shadow price. We discuss the procedure for determination of bottleneck values for diverse production environments. The Law of Diminishing Returns is shown to be a sufficient but not necessary condition for the equivalence of the average and the marginal shadow price. The equivalence of these two prices is proved for several environments. Bottleneck identification is the first step in resource acquisition decisions faced by managers. The definition of bottleneck presented in the paper has the potential to not only reduce ambiguity regarding the meaning of the term but also open a new window to the formulation and analysis of a rich set of problems faced by managers.

On the representation of the One Machine Sequencing Problem in the Shifting Bottleneck Heuristic

The Shilling Bottleneck heuristic decomposes the Job Shop problem into a series of One Machine Sequencing Problems (OMSPs) with release and due dates, precedence constraints and the minimization of maximum lateness objective. It is well known that delayed precedence constraints may exist between two operations to be performed on the same machine. We identify a new type of precedence constraint that may exist in an OMSP between the predecessor of an operation and the successor of another. The premise that an OMSP captures the sequencing relationships on other machines in the release and due date information is not valid when such precedence constraints exist. A modification of the OMSP representation is proposed based on a generalized lateness objective defined on a due window. The implications of such a representation for the OMSP solution procedure have been explored.

Detection of incorrect and inappropriateImagefrom Tweets in Social Network

Digital imaging has grown to become the prevalent technology for creating, processing, and storing digital memory and proof. Though this technology brings many leverage, it can be used as a ambiguous tool for covering details and evidences. This is because today digital images can be tampered in such supremacy that forgery cannot be find visually. In fact, the immunity concern of digital content has arisen a long time ago and different methods to verify the efficiency of digital images have been developed. Digital images offer many features for forgery detection algorithm to take precedence of specifically the color and brightness of individual pixels as well as an image�s resolution and format. These properties grant for analysis and similarity between the significance of digital forgeries in an attempt to develop an algorithm for detecting image tampering. This paper presents a technique for image copy or move image forgery detection using Radix Sort, FasterK-means clustering algorithm & DCT

Direct and indirect reciprocity among individuals and groups

Direct and indirect reciprocity are two fundamental mechanisms that promote prosocial behavior within groups and across societies. Here, we review recent work that illustrates how a (direct and indirect) reciprocity framework can illuminate our understanding of several factors related to prosocial behavior — namely group membership, gossip, and third-party punishment. We propose that each of these factors can promote prosocial behavior via proximate psychological mechanisms related to direct and indirect reciprocity: reputational concern, expectations, and anticipation of future interaction. Finally, we discuss the implications of adopting such a framework and highlight a number of avenues for future research.Social decision makin

Clinical variants of the native class d beta-lactamase of acinetobacter baumannii pose an emerging threat through ıncreased hydrolytic activity against carbapenems

The threat posed by the chromosomally encoded class D beta-lactamase of Acinetobacter baumannii (OXA-51/66) has been unclear, in part because of its relatively low affinity and turnover rate for carbapenems. Several hundred clinical variants of OXA51/66 have been reported, many with substitutions of active-site residues. We determined the kinetic properties of OXA-66 and five clinical variants with respect to a wide variety of beta-lactam substrates. The five variants displayed enhanced activity against carbapenems and in some cases against penicillins, late-generation cephalosporins, and the monobactam aztreonam. Molecular dynamics simulations show that in OXA-66, P130 inhibits the side-chain rotation of I129 and thereby prevents doripenem binding because of steric clash. A single amino acid substitution at this position (P130Q) in the variant OXA-109 greatly enhances the mobility of both I129 and a key active-site tryptophan (W222), thereby facilitating carbapenem binding. This expansion of substrate specificity represents a very worrisome development for the efficacy of beta-lactams against this troublesome pathogen.HHS \ NIH \ National Institute of Allergy and Infectious Diseases (NIAID):1R15AI082416 National Science Foundation (NSF): CNS-122829

Učinak eksrakta kore brucijskog bora (Pinus brutia) na čiste i mješovite kulture buražnih bakterija i arheja te na fermentacijske značajke buraga in vitro

The aim of the study was to investigate the effects of Pinus brutia bark extract, which is rich in polyphenolic compounds of tannins, on both pure and mixed continuous cultures of rumen bacteria and archaea, as well as on rumen fermentation characteristics in vitro. Antimicrobial susceptibility assay with pure cultures was carried out in an anaerobic chamber. Pinus brutia bark extract exhibited a potential inhibitor activity (P<0.05) against pure cultures of Ruminococcus flavefaciens, Eubacterium ruminantium, and Methanobacterium formicicum while a growth stimulatory effect (P<0.05) was observed for Ruminoccocus albus, Butyrivibrio fibrisolvens, and Streptococcus bovis. Pinus brutia bark extract only had a potential inhibitor effect (P<0.05) on R. albus at the highest dose (1200 μg/mL). Pinus brutia bark extract also stimulated (P<0.05) the growth of pure cultures of Fibrobacter succinogenes, while it did not affect Megasphaera elsdenii, except at the highest dose. The effects of two doses (75 and 375 mg/L) of P. brutia bark extract on in vitro mixed cultures and rumen fermentation parameters were determined by the rumen simulation technique (Rusitec). Supplementation with P. brutia bark extract led to a quadratic decrease (P<0.05) in the cell numbers of R. flavefaciens. Production of total and individual short chain fatty acids (SCFA), acetate to propionate ratio (C2/C3), total protozoa, ruminal pH, and dry matter digestibility (DMD) did not change in the presence of P. brutia bark extract. Supplementation with both doses of P. brutia bark extract decreased (P<0.05) the ammonia-N concentrations. Ammonia-N concentration was lowest in the high-supplemented group (P<0.05). As a conclusion, inhibitory effects of P. brutia bark extract on some species in the pure cultures were in the same direction as with mixed ruminal cultures, while stimulatory effects disappeared. The lack of inhibitory effects on protozoa and on a large number of Gram-positive rumen bacteria in the mixed cultures suggests that its mechanism of action is not exactly similar to antibiotics. Although P. brutia bark extract did not alter ruminal SCFA, it could have potential to improve ruminal protein utilization without depressing rumen microbial fermentation.Cilj ovog rada bio je istražiti učinak ekstrakta kore brucijskog bora (Pinus brutia), koji je bogat polifenolnim sastojcima tanina, na čiste i mješovite kulture buražnih bakterija i arheja kao i na in vitro fermentacijske značajke buraga. Proveden je test antimikrobne osjetljivosti s čistim kulturama u anaerobnim uvjetima. Ekstrakt kore brucijskog bora pokazao je potencijalnu inhibitornu aktivnost (P < 0,05) protiv čistih kultura bakterija Ruminococcus flavefaciens, Eubacterium ruminantium i Methanobacterium formicicum, a stimulacijski učinak na rast (P < 0,05) opažen je za bakterije Ruminoccocus albus, Butyrivibrio fibrisolvens i Streptococcus bovis. Ekstrakt kore brucijskog bora imao je potencijalan inhibitorni učinak (P < 0,05) na R. albus samo u najvećoj dozi (1200 μg/mL). Također je imao stimulacijski učinak (P < 0,05) na čiste kulture Fibrobacter succinogenes, a nije utjecao na Megasphaera elsdenii osim u najvećoj dozi. Učinak dviju doza (75 i 375 mg/L) ekstrakta kore brucijskog bora na in vitro mješovite culture i pokazatelje fermentacije u buragu određen je simulacijskom tehnikom (Rusitec). Dodatak ekstrakta kore brucijskog bora doveo je do kvadratnog smanjenja (P < 0,05) broja stanica R. flavefaciens. Nije bilo promjena u proizvodnji ukupnih i pojedinačnih kratkolančanih masnih kiselina (SCFA), omjeru acetata i propionata (C2/C3), ukupnom broju protozoa, buražnom pH i probavljivosti suhe tvari (DMD). Suplementacija objema dozama ekstrakta kore brucijskog bora smanjila je (P < 0,05) koncentracije amonijaka-N. Koncentracija amonijaka-N bila je najniža u skupini s najvećom dozom suplementa (P < 0,05). Zaključujemo da je inhibitorni učinak ekstrakta kore brucijskog bora na neke vrste u čistim kulturama bio jednak onomu u mješovitim buražnim kulturama, a nije bilo stimulacijskog efekta. Manjak inhibitornih učinaka na protozoe i na mnoge Gram-pozitivne buražne bakterije u mješovitim kulturama upućuje na to da njihov mehanizam djelovanja nije jednak onomu kod antibiotika. Premda ekstrakt kore brucijskog bora nije promijenio buražni SCFA, mogao bi poboljšati iskorištavanje proteina u buragu a da pritom ne suprimira mikrobnu fermentaciju

Transit Timing Analysis in the HAT-P-32 System

We present the results of 45 transit observations obtained for the transiting exoplanet HATP- 32b. The transits have been observed using several telescopes mainly throughout the YETI (Young Exoplanet Transit Initiative) network. In 25 cases, complete transit light curves with a timing precision better than 1.4 min have been obtained. These light curves have been used to refine the system properties, namely inclination i, planet-to-star radius ratio Rp/Rs, and the ratio between the semimajor axis and the stellar radius a/Rs. First analyses by Hartman et al. suggests the existence of a second planet in the system, thus we tried to find an additional body using the transit timing variation (TTV) technique. Taking also the literature data points into account, we can explain all mid-transit times by refining the linear ephemeris by 21 ms. Thus, we can exclude TTV amplitudes of more than ∼1.5min

Transit Timing Analysis in the HAT-P-32 system

We present the results of 45 transit observations obtained for the transiting exoplanet HAT-P-32b. The transits have been observed using several telescopes mainly throughout the YETI network. In 25 cases, complete transit light curves with a timing precision better than $1.4\:$min have been obtained. These light curves have been used to refine the system properties, namely inclination $i$, planet-to-star radius ratio $R_\textrm{p}/R_\textrm{s}$, and the ratio between the semimajor axis and the stellar radius $a/R_\textrm{s}$. First analyses by Hartman et al. (2011) suggest the existence of a second planet in the system, thus we tried to find an additional body using the transit timing variation (TTV) technique. Taking also literature data points into account, we can explain all mid-transit times by refining the linear ephemeris by 21ms. Thus we can exclude TTV amplitudes of more than $\sim1.5$min.Comment: MNRAS accepted; 13 pages, 10 figure

Constraints on a second planet in the WASP-3 system

There have been previous hints that the transiting planet WASP-3 b is accompanied by a second planet in a nearby orbit, based on small deviations from strict periodicity of the observed transits. Here we present 17 precise radial velocity measurements and 32 transit light curves that were acquired between 2009 and 2011. These data were used to refine the parameters of the host star and transiting planet. This has resulted in reduced uncertainties for the radii and masses of the star and planet. The radial-velocity data and the transit times show no evidence for an additional planet in the system. Therefore, we have determined the upper limit on the mass of any hypothetical second planet, as a function of its orbital period.Comment: Accepted for publication in The Astronomical Journa

Comparison of verona integron-borne metallo-beta-lactamase (VIM) variants reveals differences in stability and inhibition profiles

DUZGUN, AZER OZAD/0000-0002-6301-611X; Abboud, Martine I./0000-0003-2141-5988; Brem, Jurgen/0000-0002-0137-3226; McDonough, Michael A/0000-0003-4664-6942; Rydzik, Anna/0000-0003-3158-0493; DUZGUN, AZER OZAD/0000-0002-6301-611X; McDonough, Michael/0000-0003-4664-6942; Schofield, Christopher/0000-0002-0290-6565; SANDALLI, Cemal/0000-0002-1298-3687WOS: 000376490800025PubMed: 26666919Metallo-beta-lactamases (MBLs) are of increasing clinical significance; the development of clinically useful MBL inhibitors is challenged by the rapid evolution of variant MBLs. the Verona integron-borne metallo-beta-lactamase (VIM) enzymes are among the most widely distributed MBLs, with > 40 VIM variants having been reported. We report on the crystallographic analysis of VIM-5 and comparison of biochemical and biophysical properties of VIM-1, VIM-2, VIM-4, VIM-5, and VIM-38. Recombinant VIM variants were produced and purified, and their secondary structure and thermal stabilities were investigated by circular dichroism analyses. Steady-state kinetic analyses with a representative panel of beta-lactam substrates were carried out to compare the catalytic efficiencies of the VIM variants. Furthermore, a set of metalloenzyme inhibitors were screened to compare their effects on the different VIM variants. the results reveal only small variations in the kinetic parameters of the VIM variants but substantial differences in their thermal stabilities and inhibition profiles. Overall, these results support the proposal that protein stability may be a factor in MBL evolution and highlight the importance of screening MBL variants during inhibitor development programs.Rhodes Trust; Scientific and Technology Council of Turkey; Recep Tayyip Erdogan Universitesi Research FundRecep Tayyip Erdogan University [BAP-2013.102.03.13]; Medical Research CouncilMedical Research Council UK (MRC) [MR/L007665/1]; Medical Research Council/Canadian Grant [G1100135]; Biochemical Society Krebs Memorial Award; Medical Research CouncilMedical Research Council UK (MRC) [G1100135, MR/N002679/1] Funding Source: researchfishThe Rhodes Trust provided funding to Anne Makena. Scientific and Technology Council of Turkey provided funding to Cemal Sandalli. Recep Tayyip Erdogan Universitesi Research Fund provided funding to Aysegul Saral, Aysegul C. Cicek, and Cemal Sandalli under grant number BAP-2013.102.03.13. Medical Research Council provided funding to Jurgen Brem, Michael A. McDonough, Anna M. Rydzik, and Christopher J. Schofield under grant number MR/L007665/1. Medical Research Council/Canadian Grant provided funding to Jurgen Brem, Michael A. McDonough, Anna M. Rydzik, and Christopher J. Schofield under grant number G1100135. Biochemical Society Krebs Memorial Award provided funding to Martine I. Abboud