Management Thinking in the Earned Value Method System and the Last Planner System

Management theory has been neglected in the construction industry, which has rather focused on best practices. This paper investigates the theories implicit in two prevalent project control systems: the earned value method (EVM) and the last planner system (LPS). The study introduces two fundamental and competing conceptualizations of management: managing by means (MBM) and managing by results (MBR). The EVM is found to be based on MBR. However, project control based on MBR is argued to be inappropriate for managing at the operational level where tasks are highly interdependent. The LPS is found to be based on the MBM view. The empirical evidence from literature and case study suggested that the MBM view is more appropriate to manage works when it is applied to the operation level where each task is highly interdependent.     

Using intermediate objects to improve the efficiency of visual search

When using a mobile camera to search for a target object, it is often important to maximize the efficiency of the search. We consider a method for increasing efficiency by searching only those subregions that are especially likely to contain the object. These subregions are identified via spatial relationships. Searches that use this method repeatedly find an “intermediate” object that commonly participates in a spatial relationship with the target object, and then look for the target in the restricted region specified by this relationship. Intuitively, such searches, calledindirect searches, seem likely to provide efficiency increases when the intermediate objects can be recognized at low resolutions and hence can be found with little extra overhead, and when they significantly restrict the area that must be searched for the target. But what is the magnitude of this increase, and upon what other factors does efficiency depend? Although the idea of exploiting spatial relationships has been used in vision systems before, few have quantitatively examined these questions. We present a mathematical model of search efficiency that identifies the factors affecting efficiency and can be used to predict their effects. The model predicts that, in typical situations, indirect search provides up to an 8-fold increase in efficiency. Besides being useful as an analysis tool, the model is also suitable for use in an online system for selecting intermediate objects.     

Enhancing nanoparticle deposition using actuated synthetic cilia

We use computational modeling to probe the utility of actuated synthetic cilia lining walls of a microfluidic channel for enhancing the deposition of nanoparticles dispersed in a viscous fluid filling the channel. We demonstrate that elastic cilia actuated by a sinusoidal force applied to their free ends generate circulatory secondary flows facilitating nanoparticle transport. We identify optimal operational conditions in which the effect of cilia beating on particle deposition is maximized. Our simulations also reveal that cilia transition to a three-dimensional beating pattern when the actuation force exceeds a critical value. This transition is associated with buckling instability experienced by elastic cilia. Our findings guide the optimal design of ciliated microfluidic systems for uses such as deposition of particulates onto sensory surfaces and microfluidic mixing.     

Early pregnancy diagnosis in alpaca (Lama pacos) and llama (Lama glama) by ultrasound

An ultrasonography study of early pregnancy diagnosis was carried out in 19 alpacas and 12 llamas, after controlled matings. The aim was to determine the earliest gestational age at which pregnancy diagnosis by transrectal ultrasonography could be achieved, and to generate an empirical formula for gestational sac diameter (GSD) growth as a function of gestational age (GA), allowing an estimate of GA during the first month of pregnancy. We found that pregnancy diagnosis may be carried out as early as 9 days after mating in alpacas and 7 days in llamas. This diagnosis was found to be accurate at 23 days in alpacas and 34 days in llamas. The empirical relations that best describe the relationship between GSD and GA were GA = logGSD + 1.2339/0.0585 r = 0.85; P < 0.001 in alpacas, and GA = logGSD + 1.2649/0.0546 r = 0.77, P < 0.001 in llamas, where GA is measured in days and GSD in centimeters. Our results also indicate that ultrasonography is a reliable technique for early pregnancy diagnosis. Furthermore, the empirical formulae reliably make it possible to estimate GA from GSD during the first month of pregnancy and their use might improve the efficiency of camelid breeders.     

Development of AIDS in a chimpanzee infected with human immunodeficiency virus type 1

The condition of a chimpanzee (C499) infected with three different isolates of human immunodeficiency virus type 1 (HIV-1) for over 10 years progressed to AIDS. Disease development in this animal was characterized by (i) a decline in CD4+ cells over the last 3 years; (ii) an increase in viral loads in plasma; (iii) the presence of a virus, termed HIV-1JC, which is cytopathic for chimpanzee peripheral blood mononuclear cells; and (iv) the presence of an opportunistic infection and blood dyscrasias. Genetic analysis of the V1-V2 region of the envelope gene of HIV-1JC showed that the virus present in C499 was significantly divergent from all inoculating viruses (> or = 16% divergent at the amino acid level) and was suggestive of a large quasispecies. Blood from C499 transfused into an uninfected chimpanzee (C455) induced a rapid and sustained CD4+-cell decline in the latter animal, concomitant with high plasma viral loads. These results show that HIV-1 can induce AIDS in chimpanzees and suggest that long-term passage of HIV-1 in chimpanzees can result in the development of a more pathogenic virus.     

Antiviral properties of 3-quinolinecarboxamides: a series of novel non-nucleoside antiherpetic agents

Despite the long history in medicine, the pathophysiological mechanism(s) of seasonal affective disorder (SAD) remain largely unknown. By employing a meta-analytic methodology, the authors of this study attempted to verify the validity of different pathophysiological mechanism(s) proposed for SAD. The findings showed that for phototherapy of medium light intensity, a combination of morning-evening therapy regime yielded the best therapeutic effect, and the antidepressant effect of the morning-evening light regime was superior to a single pulse of light administered at other times of day. Furthermore, the data showed that the antidepressant effect of a single pulse of light was similar for morning, midday, and evening light. These findings supported the photon-count hypothesis and refuted the proposed photoperiod, melatonin, and phase-shifting models of SAD.     

Accuracy of localizing radiopaque markers by abdominal radiography and correlation between their gastric emptying rate and that of a canned food in dogs

OBJECTIVES: To determine accuracy of abdominal radiography in locating radiopaque markers in the gastrointestinal tract and to assess correlation between gastric emptying rate of radiopaque markers and that of canned food. ANIMALS: 17 healthy dogs. PROCEDURE: Dogs were fed thirty 1.5-mm markers and ten 5-mm markers mixed in sufficient food to meet 25% of their daily caloric intake. They were then euthanatized by administration of an overdose of barbiturate at 1, 2, 5, 8, or 12 hours after eating and the abdomen was radiographed. The stomach, small intestine, and large intestine were then separated and radiographed in isolation. The wet and dry weights of the stomach contents were determined. The apparent and actual locations of the markers and the gastric emptying rates of markers, wet matter, and dry matter were compared, using rank correlation. RESULTS: All comparisons indicated significant (P < 0.025), high correlation coefficients (> 0.92). The mean difference between the apparent and actual locations of the markers was < 3% for all comparisons. The mean difference between the percentage of small markers and large markers retained in the stomach and that of dry matter was 7.8 (SD, 6.2; range, 0 to 18%) and 11.9 (SD, 12.5; range, 0 to 44%), respectively. CONCLUSIONS: The gastric emptying and orocolic transit rates of the markers were accurately predicted by abdominal radiography. The gastric emptying rate of the diet and the small markers and, to a lesser extent, the large markers was closely correlated. CLINICAL RELEVANCE: When fed with a special canned food diet, radiopaque markers can be used to assess the gastric emptying rate of food with sufficient accuracy for clinical purposes.     

Recent update on the PPAR alpha-null mouse

The most important commercially available nitro- and aminobenzenes and the explosive trinitrobenzene were tested for mutagenicity in the Salmonella typhymurium TA 98 and TA 100 both in the absence and presence of S 9. Ten of the 14 compounds tested (71%) were mutagenic. All the substances showed positive results in TA 98 and 4 substances were also mutagenic in TA 100. The three diaminobenzenes and 4-nitroaniline were mutagenic only with metabolic activation. All other compounds did not require the addition of S 9. Only nitrobenzene, 1,2-dinitrobenzene, aniline and 2-nitroaniline were negative in both strains. In summary, all substances that are derived from nitrobenzene or aniline by addition of a nitro group in the meta- or para-position were mutagenic, whereas nitrobenzene and aniline themselves and their ortho-derivates were nonmutagenic. The possible relationships between the position of the substituents and the mutagenicity are discussed.     

Congenital muscular torticollis: magnetic resonance imaging and ultrasound diagnosis

According to figures published by the College of Health, 34,837 patients were waiting for in-patient plastic surgery treatment nationwide in 1986. By 1989 this number had increased to 40,085--an increase of 15%. Out of this waiting list, nearly 2000 patients were waiting in Manchester in 1990. Increasing public concern over the length of surgical waiting lists forced the Government to allocate extra resources to reduce both waiting lists and waiting times. We have reviewed the extra work done on a waiting list initiative scheme in Manchester in one year, from 1 August 1990 to 31 July 1991. The waiting list was reduced by 932 patients in one year. The attendance rate of the patients for surgery was excellent and the patients in general were very grateful for having had the treatment. The problems associated with setting us such schemes are enormous and are discussed in detail, with alternative suggestions for preventing waiting lists from building up again in future.