Scheduling in a two-machine flowshop for the minimization of the mean absolute deviation from a common due date

This paper addresses the minimization of the mean absolute deviation from a common due date in a two-machine flowshop scheduling problem. We present heuristics that use an algorithm, based on proposed properties, which obtains an optimal schedule fora given job sequence. A new set of benchmark problems is presented with the purpose of evaluating the heuristics. Computational experiments show that the developed heuristics outperform results found in the literature for problems up to 500 jobs. (C) 2007 Elsevier Ltd. All rights reserved.

Photochemical heat-shock response in common bean leaves as affected by previous water deficit

The heat sensitivity of photochemical processes was evaluated in the common bean (Phaseolus vulgaris) cultivars A222, A320, and Carioca grown under well-watered conditions during the entire plant cycle (control treatment) or subjected to a temporal moderate water deficit at the preflowering stage (PWD). The responses of chlorophyll fluorescence to temperature were evaluated in leaf discs excised from control and PWD plants seven days after the complete recovery of plant shoot hydration. Heat treatment was done in the dark (5 min) at the ambient CO2 concentration. Chlorophyll fluorescence was assessed under both dark and light conditions at 25, 35, and 45 degrees C. In the dark, a decline of the potential quantum efficiency of photosystem II (PSII) and an increase in minimum chlorophyll fluorescence were observed in all genotypes at 45 degrees C, but these responses were affected by PWD. In the light, the apparent electron transport rate and the effective quantum efficiency of PSII were reduced by heat stress (45 degrees C), but no change due to PWD was demonstrated. Interestingly, only the A222 cultivar subjected to PWD showed a significant increase in nonphotochemical fluorescence quenching at 45 degrees C. The common bean cultivars had different photochemical sensitivities to heat stress altered by a previous water deficit period. Increased thermal tolerance due to PWD was genotype-dependent and associated with an increase in potential quantum efficiency of PSII at high temperature. Under such conditions, the genotype responsive to PWD treatment enhanced its protective capacity against excessive light energy via increased nonphotochemical quenching.

Liberibacters associated with orange jasmine in Brazil: incidence in urban areas and relatedness to citrus liberibacters

Two surveys (2005/2006 and 2009) were conducted in the state of Sao Paulo, Brazil, to investigate the incidence of `Candidatus Liberibacter asiaticus` and `Ca. L. americanus`, two liberibacters associated with citrus huanglongbing (HLB) disease and both transmitted by Diaphorina citri, in orange jasmine (Murraya exotica), a widespread ornamental tree in cities and villages. The graft-transmissibility of the two species, and their DNA relatedness to citrus-associated liberibacters, were also investigated. Quantitative PCR was applied to PCR-positive orange jasmine and HLB-positive citrus growing in backyards and orchards to assess their inoculum source potentials. Liberibacters were detected in 91 of 786 sampled orange jasmine plants in 10 of 76 sampled locations. PCR-positive trees exhibited yellow shoots and/or dieback symptoms indistinguishable from those on PCR-negative trees. `Candidatus Liberibacter americanus` was more common in 2005/2006 (96 center dot 6%) and `Ca. L. asiaticus` in 2009 (84 center dot 8%). rplJ nucleotide sequences were identical within all populations of either species. Graft transmission succeeded only in homologous host combinations, including `Ca. L. americanus` (2/10) from/to orange jasmine and `Ca. L. americanus` (5/18) and `Ca. L. asiaticus` (5/9) from/to citrus. Symptoms were mild and developed less rapidly in orange jasmine than in citrus, probably as a result of lower liberibacter multiplication rates. Respective titres of `Ca. L. americanus` and `Ca. L. asiaticus` in orange jasmine averaged 4 center dot 3 and 3 center dot 0 log cells g-1 tissue, compared with 5 center dot 5 and 7 center dot 3 in citrus. The results indicate that orange jasmine does not favour liberibacter multiplication as much as citrus. However, its importance in HLB epidemics should not be underestimated as it is a preferred host of D. citri and is not under any strict tree-eradication programme or measures for insect control.

Extension of the core map of common bean with EST-SSR, RGA, AFLP, and putative functional markers

Microsatellites and gene-derived markers are still underrepresented in the core molecular linkage map of common bean compared to other types of markers. In order to increase the density of the core map, a set of new markers were developed and mapped onto the RIL population derived from the `BAT93` x `Jalo EEP558` cross. The EST-SSR markers were first characterized using a set of 24 bean inbred lines. On average, the polymorphism information content was 0.40 and the mean number of alleles per locus was 2.7. In addition, AFLP and RGA markers based on the NBS-profiling method were developed and a subset of the mapped RGA was sequenced. With the integration of 282 new markers into the common bean core map, we were able to place markers with putative known function in some existing gaps including regions with QTL for resistance to anthracnose and rust. The distribution of the markers over 11 linkage groups is discussed and a newer version of the common bean core linkage map is proposed.

Inheritance of growth habit detected by genetic linkage analysis using microsatellites in the common bean (Phaseolus vulgaris L.)

The genetic linkage map for the common bean (Phaseolus vulgaris L.) is a valuable tool for breeding programs. Breeders provide new cultivars that meet the requirements of farmers and consumers, such as seed color, seed size, maturity, and growth habit. A genetic study was conducted to examine the genetics behind certain qualitative traits. Growth habit is usually described as a recessive trait inherited by a single gene, and there is no consensus about the position of the locus. The aim of this study was to develop a new genetic linkage map using genic and genomic microsatellite markers and three morphological traits: growth habit, flower color, and pod tip shape. A mapping population consisting of 380 recombinant F10 lines was generated from IAC-UNA x CAL143. A total of 871 microsatellites were screened for polymorphisms among the parents, and a linkage map was obtained with 198 mapped microsatellites. The total map length was 1865.9 cM, and the average distance between markers was 9.4 cM. Flower color and pod tip shape were mapped and segregated at Mendelian ratios, as expected. The segregation ratio and linkage data analyses indicated that the determinacy growth habit was inherited as two independent and dominant genes, and a genetic model is proposed for this trait.

Nitrogen fertilization in common bean crops under no-tillage and conventional systems.

Nitrogen fertilization in common bean crops under no-tillage and conventional systems. Nitrogen fertilizer is necessary for high yields in common bean crops and N responses under conditions of no-tillage and conventional systems are still basic needs. Thus, the objective of this research was to evaluate the effect of N application and common bean yield in no-tillage and conventional systems. The experimental design was a randomized block in a factorial scheme (2x8+1) with four replications. The treatments were constituted by the combination of two N doses (40 and 80 kg ha(-1)) applied at side dressing at eight distinct stadia during vegetative development of the common bean (V(4-3), V(4-4), V(4-5), V(4-6), V(4-7), V(4-8), V(4-9) and V(4-10)), in addition to a control plot without N in side dressing. The experiment was conducted over two years (2002 and 2003) in no-tillage on millet crop residues and conventional plow system. It was concluded that N fertilizer at the V(4) stadium of common bean promotes similar seed yields in no-tillage and conventional systems. Yield differences between no-tillage and conventional systems are inconsistent in the same agricultural area.

Nitrogen in common bean in no-tillage system over gramineae

An adequate supply of nitrogen is essential for high yield of common bean seeds; however, the responses to this nutrient in no-tillage systems can vary in function of the species and the amount of straw present. The aim of this research was to evaluate response of the common bean to N in no-tillage systems over maize, millet and Brachiaria brizantha crop residues. Three experiments were conducted, one for each gramineous species. The experimental design was a randomized block in a 5x2x2 factorial scheme, with five N doses (0, 30, 60, 90, 120 kg ha(-1)), in two distinct stadia during the vegetative development (3(rd) and 6(th) trifoliate leaf) and two common bean cultivars (IPR Juriti and Perola), with four replications. The IPR Juriti produced a greater number of pods per plant and showed lower mass per 100 seeds than Perola. It did not show variation in bean yield when the sidedressing N application was carried out in the 3(rd) or 6(th) trifoliate leaf stadia. Based on the obtained results, one concludes that the seed productivity of common beans increases linearly with N doses in a no-tillage system over maize residues.

Mycovirus in Pseudocercospora griseola, the causal agent of angular leaf spot in common bean

Pseudocercospora griseola (Sacc.) Crous &. Braun is a widespread fungal phytopathogen that is responsible for angular leaf spot in the common bean (Phaseolus vulgaris L.). A number of fungal phytopathogens have been shown to harbour mycoviruses, and this possibility was investigated in populations of Pseudocercospora griseola. The total nucleic acid extracts of 61 fungal isolates were subjected to agarose gel electrophoresis. Small fragments (800-4800 bp) could be identified in 42 of the samples. The presence of dsRNA in isolate Ig838 was confirmed by treatment of total nucleic acid with DNase, RNase A, and nuclease S I. Transmission electron microscopy revealed the presence of viral-like particles 40 nm in diameter in the mycelia of 2 fungal isolates, namely 29-3 and Ig838. The transmission of dsRNA by means of conidia was 100% for isolate 29-3, but there was loss of 1-6 fragments of dsRNA in monosporic colonies of isolate Ig848. Cycloheximide treatment failed to inhibit the mycovirus in isolate 29-3, but proved efficient in the elimination of the 2.2, 2.0, 1.8, 1.2 and 1.0 kb fragments in 2 colonies of isolate Ig848. The occurrence of a mycovirus in Pseudocercospora griseola was demonstrated for the first time in the present study.

Orchid fleck symptoms may be caused naturally by two different viruses transmitted by Brevipalpus

Brevipalpus-transmitted viruses (BTV) cause chlorotic, necrotic and/or ringspot lesions in leaves and stems of orchids, citrus, coffee and several other plant species. There are two different types of BTVs, the nuclear and the cytoplasmic, based on maturation locale in the cell and particle morphology. The orchid fleck virus (OFV) is a BTV that infects orchids. Its short rodlike particles are 32-40 nm in diameter, 100-150 nm in length. OFV is found in the nucleus and is associated with intranuclear electronlucent viroplasms. In 1999, transmission electron microscopy analysis revealed a distinct type of virus causing orchid fleck symptoms. The bacilliform particles, 70-80 nm in diameter and 110-120 nm in length, induced electron-dense viroplasm inclusions in infected cells and resembled the cytoplasmic type associated with BTV, such as the citrus leprosis virus C. Our objective in the present study was to verify whether the cytoplasmic type virus found in orchids could be amplified using primers for other cytoplasmic BTVs, such as CiLV-C and Solanum violaefolium ringspot virus (SvRSV). Additionally, we aimed to differentiate the two BTVs found in orchids: the nuclear and the cytoplasmic types of OFV using microscopy and molecular and serological tools. This virus was not amplified by the CiLV-C and SvRSV primers, and neither the molecular nor the serological tools available to the OFV diagnosis reacted with it, demonstrating that they are definitely different viruses.

Phytoplasma closely related to the pigeon pea witches`-broom phytoplasma (16Sr IX) is associated with citrus huanglongbing symptoms in the state of Sao Paulo, Brazil

In February 2007, sweet orange trees with characteristic symptoms of huanglongbing (HLB) were encountered in a region of Sao Paulo state (SPs) hitherto free of HLB. These trees tested negative for the three liberibacter species associated with HLB. A polymerase chain reaction (PCR) product from symptomatic fruit columella DNA amplifications with universal primers fDI/rPI was cloned and sequenced. The corresponding agent was found to have highest 16S rDNA sequence identity (99%) with the Pigeon pea witches`-broom phytoplasma of group 16Sr IX. Sequences of PCR products obtained with phytoplasma 16S rDNA primer pairs fU5/rU3, fU5/P7 confirm these result.,;. With two primers D7f2/D7r2 designed based oil the 16S rDNA Sequence of the cloned DNA fragment, positive amplifications were obtained from more than one hundred samples including symptomatic fruits and blotchy mottle leaves. Samples positive for phytoplasmas were negative for liberibacters, except for four samples, which were positive for both the phytoplasma and `Candidatus Liberibacter asiaticus`. The phytoplasma was detected by electron microscopy in the sieve tubes of midribs from symptomatic leaves. These results Show that a phytoplasma of group IX is associated with citrus HLB symptoms ill northern, central, and Southern SPs. This phytoplasma has very probably been transmitted to citrus from an external Source of inoculum, but the Putative insect vector is not yet known.

A common matrix metalloproteinase (MMP)-2 polymorphism affects plasma MMP-2 levels in subjects environmentally exposed to mercury

Mercury (Hg) exposure is associated with disease conditions, including cardiovascular problems. Although the mechanisms implicated in these complications have not been precisely defined yet, matrix metalloproteinases (MMPs) may be involved. The gene encoding MMP-2 presents genetic polymorphisms which affect the expression and activity level of this enzyme. A common polymorphism of MMP-2 gene is the C(-1306)T (rs 243865), which is known to disrupt a Sp1-type promoter site (CCACC box), thus leading to lower promoter activity associated with the T allele. This study aimed at examining how this polymorphism affects the circulating MMP-2 levels and its endogenous inhibitor, the tissue inhibitor of metalloproteinase-2 (TIMP-2) in 210 subjects environmentally exposed to Hg. Total blood and plasma Hg concentrations were determined by inductively coupled plasma-mass spectrometry (ICP-MS). MMP-2 and TIMP-2 concentrations were measured in plasma samples by gelatin zymography and ELISA, respectively. Genotypes for the C(-1306)T polymorphism were determined by Taqman (R) Allele Discrimination assay. We found a positive association (p = 0.0057) between plasma Hg concentrations and MMP-2/TIMP-2 (an index of net MMP-2 activity). The C(-1306)T polymorphism modified MMP-2 concentrations (p = 0.0465) and MMP-2/TIMP-2 ratio (p = 0.0060) in subjects exposed to Hg, with higher MMP-2 levels been found in subjects carrying the C allele. These findings suggest a significant interaction between the C(-1306)T polymorphism and Hg exposure, possibly increasing the risk of developing diseases in subjects with the C allele. (C) 2011 Elsevier B.V. All rights reserved.

Circulating Interleukin-6 and High-Sensitivity C-Reactive Protein Decrease After Periodontal Therapy in Otherwise Healthy Subjects

Background: Periodontal disease has been associated with many chronic inflammatory systemic diseases, and a common chronic inflammation pathway has been suggested for these conditions. However, few studies have evaluated whether periodontal disease, in the absence of other known inflammatory conditions and smoking, affects circulating markers of chronic inflammation. This study compared chronic inflammation markers in control individuals and patients with periodontal disease and observed whether non-surgical periodontal therapy affected inflammatory disease markers after 3 months. Methods: Plasma and serum of 20 controls and 25 patients with periodontal disease were obtained prior to and 3 months after non-surgical periodontal therapy. All patients were non-smokers, they did not use any medication, and they had no history or detectable signs and symptoms of systemic diseases. Periodontal and systemic parameters included probing depth, bleeding on probing, clinical attachment level, hematologic parameters, as well as the following inflammatory markers: interleukin (IL)-6, high-sensitivity C-reactive protein (hs-CRP), CD40 ligand, monocyte chemoattractant protein (MCP)-1, soluble P-selectin (sP-selectin), soluble vascular adhesion molecule (sVCAM)-1, and soluble intercellular adhesion molecule (sICAM)-1. Results: There were no differences in the hematologic parameters of the patients in the control and periodontal disease groups. Among the tested inflammatory markers, IL-6 concentrations were higher in the periodontal disease group at baseline compared to the controls (P=0.006). Therapy was highly effective (P<0.001 for all the analyzed clinical parameters), and a decrease in circulating IL-6 and hs-CRP concentrations was observed 3 months after therapy (P=0.001 and P=0.006, respectively). Our results also suggest that the CD40 ligand marker may have been different in the control and periodontal disease groups prior to the therapy (P=0.009). Conclusions: In apparently otherwise healthy patients, periodontal disease is associated with increased circulating concentrations of IL-6 and hs-CRP, which decreased 3 months after non-surgical periodontal therapy. With regard to the CD40 ligand, MCP-1, sP-selectin, sVCAM-1, and sICAM-1, no changes were seen in the periodontal disease group between baseline and 3 months after therapy. J Periodontol 2009;80:594-602.

A randomised control trial of exercise and manipulative therapy for cervicogenic headache

Study Design. A multicenter, randomized controlled trial with unblinded treatment and blinded outcome assessment was conducted. The treatment period was 6 weeks with follow-up assessment after treatment, then at 3, 6, and 12 months. Objectives. To determine the effectiveness of manipulative therapy and a low-load exercise program for cervicogenic headache when used alone and in combination, as compared with a control group. Summary of Background Data. Headaches arising from cervical musculoskeletal disorders are common. Conservative therapies are recommended as the first treatment of choice. Evidence for the effectiveness of manipulative therapy is inconclusive and available only for the short term. There is no evidence for exercise, and no study has investigated the effect of combined therapies for cervicogenic headache. Methods. In this study, 200 participants who met the diagnostic criteria for cervicogenic headache were randomized into four groups: manipulative therapy group, exercise therapy group, combined therapy group, and a control group. The primary outcome was a change in headache frequency. Other outcomes included changes in headache intensity and duration, the Northwick Park Neck Pain Index, medication intake, and patient satisfaction. Physical outcomes included pain on neck movement, upper cervical joint tenderness, a craniocervical flexion muscle test, and a photographic measure of posture. Results. There were no differences in headache-related and demographic characteristics between the groups at baseline. The loss to follow-up evaluation was 3.5%. At the 12-month follow-up assessment, both manipulative therapy and specific exercise had significantly reduced headache frequency and intensity, and the neck pain and effects were maintained (P < 0.05 for all). The combined therapies was not significantly superior to either therapy alone, but 10% more patients gained relief with the combination. Effect sizes were at least moderate and clinically relevant. Conclusion. Manipulative therapy and exercise can reduce the symptoms of cervicogenic headache, and the effects are maintained.