Optimising Parcel Deliveries in London Using Dual-Mode Routing

Last-mile delivery operations are complex, and the conventional way of using a single mode of delivery (e.g. driving) is not necessarily an efficient strategy. This paper describes a two-level parcel distribution model that combines walking and driving for a single driver. The model aims to minimise the total travelling time by scheduling a vehicle's routing and the driver's walking sequence when making deliveries, taking decisions on parking locations into consideration. The model is a variant of the Clustered Travelling Salesman Problem with Time Windows, in which the sequence of visits within each cluster is required to form a closed tour. When applied to a case study of an actual vehicle round from a parcel carrier operating in London, savings of over 20% in the total operation time were returned over the current situation where 104 transactions from 99 consignees were being delivered to 57 stopping points

Quantitative microbial risk assessment: Research status and future development

Quantitative Microbial Risk Assessment (QMRA) is much more developed and applied in developed countries than in developing world although risk assessment of pathogen exposure is increased in developing countries due to the unhygienic condition and (re)emerging infectious diseases. However, QMRA needs further methodological development to improve its usefulness. We argue that promoting the use and development of QMRA in developing countries and identifying its methodological gaps to be filled in future are needed. This paper aims to have an overview on the usage of this method in scientific community worldwide and discuss possible directions for the application and research of QMRA. We systematically searched peer-reviewed publication on QMRA from until December 2011. We found 463 papers related to QMRA but the majority of these (91%) were published in the 2000s. Only 3.5% of the papers were published by authors from developing countries, meaning that this method is developed and extensively used in developed world, in particular US, Europe and Australia. QMRA has been applied mainly in the domain of food (54.2%) and water (9.5%, mostly for drinking water) and less focused on sanitation (6.5%), waste and recreational water and others. The number of studies on dose-response assessment increases, whereas information on exposure assessment is limited and relies mainly on assumption. Application of statistics and integration of parameters such as exposure time, age and immunity of the host into the dose-response model is observed. However, dose-response models need to be developed for other remaining pathogens, in particular new emerging infectious diseases and further studies on exposures needed. Researchers from developing countries would need to be more proactive in using and developing QMRA in partnership with experienced researchers from developed countries

Effect of modified atmosphere packaging on chilling-induced peel browning in banana

Sucrier bananas (Musa AA Group; cultivar locally known as Kluai Khai) were stored at 10degreesC, which results in chilling injury (CI). Fruit was held in packages with and without a modified atmosphere (MA). Oxygen levels in the MA packages were about 12% while CO2 concentrations were about 4%. MA packaging resulted in less visible CI (i.e. greyish peel browning). Total free phenolics in the peel of control bananas decreased more rapidly than in fruit held in the MA package. Phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) activities in the peel of control bananas were considerably higher than in MA-packed fruit. Pulp softness, sweetness and flavour of MA-packed fruit were better than in control fruit. MA thus reduced CI symptoms. PAL and PPO activities may be causally related to Cl-induced peel browning. (C) 2003 Elsevier B.V. All rights reserved

Relationship between browning and the activities of polyphenol oxidase and phenylalanine ammonia lyase in banana peel during low temperature storage

Kluai Khai (Musa AA Group) and Kluai Hom Thong (Musa AAA Group) bananas were stored at 6 and 10 °C. Visible chilling injury (CI) in the peel, mainly browning, occurred at both temperatures, but more so at 6 °C, and without significant differences between the cultivars. At the time of harvest, total free phenolics in the peel were three times lower in Kluai Khai than in Kluai Hom Thong fruit, the polyphenol oxidase (PPO) activity in Kluai Khai being considerably higher and phenylalanine ammonia lyase (PAL) activity much lower. As CI developed, PAL and PPO activities in the peel increased, and total free phenolics decreased. The decrease in total free phenolic compounds and the increase in PAL and PPO activities occurred more rapidly at 6 °C than at 10 °C, in both banana cultivars. Correlations between visible CI and the level of total free phenolics, and between CI and the activities of PPO and PAL, were all highly significant. The results indicate that low temperature stress induced concerted activities of PAL and PPO, which resulted in browning. Since the concentrations of free phenolic compounds and the rate of PAL and PPO activities varied considerably between the two cultivars, but browning did not, the changes in the biochemical parameters rather than their absolute levels were correlated with peel browning

Patterns of risky sexual behaviors and associated factors among youths and adolescents in Vietnam

10.3390/ijerph17061903International Journal of Environmental Research and Public Health176190

Isolation and characterization of a DREB homolog gene from a local drought-tolerant maize cultivar

Clarifying the genetic background of the drought-tolerance trait is a crucial task that may help to improve plant performance under stress by a genetic engineering approach. dehydration-responsive element-binding protein (dREB) is a transcription factor family which modulates many stress-responsive genes. In this study, we isolated a DrEB homolog gene named ZmDrEBtv from Zea mays var. Tevang-1. Using bioinformatic tools, a number of Indels and SNPs in ZmDrEBtv sequence different from the reference accession were identified. In addition, based on deduced protein sequence similarity, ZmdREBtv was assigned to transcription factor dREB2 class as featured by a conserved dNa binding domain – aP2. The ZmDrEBtv construct under thecontrol of the rd29a promoter was transformed into a drought-sensitive maize plant, K7 line. The transgenic plants were assessed with reference to molecular and phenotypic characteristics related to the drought-tolenrance trait. The results proved that the maize plants carrying ZmDrEBtv gene showed enhanced tolerance and better performance to the water-deficit environment at different stages, compared to the wild-type plants

AsiFood and its output and prospects: An Erasmus+ project on capacity building in food safety and quality for South-East Asia

Erasmus +, 561630-EPP-1-2015-1-FR-EPPKA2-CBHE-JP, ASIFOOD : Universities as key partners for the new challenges regarding food safety & quality in ASEA

Temperature and modified atmosphere affect the quality of okra Temperatura e atmosfera modificada influenciam a qualidade do quiabo

Little information is available on the influence of temperature on plastic films wrapped okra (Albelmoschus esculentus) for their postharvested conservation. This works investigated the influence of the temperature and PVC film on the development of chilling injury and storability from one of the most popular Brazilian cultivar of okra cv. Amarelinho in fruits stored at 5, 10ºC and at 25ºC. Fruits were harvest at commercial maturity stage with length ranging from 8 to 12 cm, and immediately wrapped in PVC over a polystyrene tray and than stored until visible deterioration or wilting symptoms. Lowering the temperature of storage room from 25 to 10 or 5ºC decreased the weight loss in both PVC wrapped and control fruits, with a lower rate at 5ºC. By reducing the temperature to 5 or 10ºC and wrapping the fruits in PVC film, the relative water content of the fruit pericarp was maintained throughout the storage, while at 25ºC the high weight loss was associated with significant reduction of the water content. The development of chilling symptoms was delayed by the presence of PVC film in fruits stored at 5ºC. However, at 10ºC symptoms of pitting were not developed in PVC wrapped or control fruits up to tenth day of storage. The rate of chlorophyll degradation was diminished by reducing the temperature and by wrapping the fruits with PVC film. The appearance of severe chilling symptoms at 5ºC was associated to less chlorophyll in the fruit pericarp on the control as compared to their content in the PVC wrapped fruits.<br>Para o armazenamento do quiabo (Albelmoschus esculentus) há poucas informações disponíveis sobre a influência da temperatura e filmes plásticos na conservação pós-colheita desta hortaliça. Para investigar a influência da temperatura e do filme de PVC na qualidade e desenvolvimento de sintomas de injúria por frio de uma das mais populares cultivares brasileira de quiabo cv. Amarelinho, os frutos foram armazenados a 5, 10 e 25ºC. Os frutos foram colhidos no estádio de maturação comercial, com comprimento entre 8 e 12 cm, sendo então envoltos por uma camada de filme de PVC em bandeja de poliestireno expandido, seguido do armazenamento até o aparecimento de sintomas de deterioração ou murcha. A redução da temperatura de armazenamento de 25 para 10 ou 5ºC diminuiu a perda de massa nos frutos envoltos com PVC e dos frutos controle, com menor taxa a 5ºC. Ao reduzir a temperatura para 5 ou 10ºC e cobrir com filme de PVC, o conteúdo relativo de água foi mantido durante o armazenamento, porém a 25ºC a elevada perda de massa esteve associada a significante redução do conteúdo de água do pericarpo do fruto. O aparecimento de sintomas de injúria por frio foi retardado pela presença de filme de PVC nos frutos armazenados a 5ºC. No entanto a 10ºC, não foram detectados sintomas de degeneração associados à injúria por frio nos frutos envoltos com PVC ou controle até o décimo dia de armazenamento. A taxa de degradação de clorofila durante o armazenamento foi menor nos frutos mantidos nas temperaturas mais baixas e com filme PVC. O aparecimento de sintomas severos de injúria por frio a 5ºC relacionou-se com o menor conteúdo de clorofila dos frutos controle, quando comparado àqueles envoltos em filme de PVC

Vida útil e metabolismo de carboidratos em raízes de mandioquinha-salsa sob refrigeração e filme de PVC Shelf life and carbohydrate metabolism of arracacha roots stored under refrigeration and PVC film

O objetivo deste trabalho foi avaliar a influência da temperatura de armazenamento e do uso do filme de cloreto de polivinila (PVC) sobre a perda de matéria fresca e água, incidência de danos causados por frio e metabolismo pós-colheita dos carboidratos, em raízes tuberosas de mandioquinha-salsa (Arracacia xanthorrhiza). O filme de PVC reduziu a perda de matéria fresca e manteve o teor de água das raízes, durante o armazenamento por 60 dias a 5 e 10ºC. Os danos causados por frio foram inibidos nas raízes embaladas em filme de PCV, em ambas as temperaturas de armazenamento. As baixas temperaturas induziram o acúmulo de açúcares solúveis e a degradação de amido e, para as raízes armazenadas sem PVC, o aumento do conteúdo dos açúcares solúveis foi transiente e a taxa de degradação de amido foi superior à das raízes armazenadas com PVC.<br>The objective of this work was to evaluate the influence of the storage temperature and stretch polyvinylchloride (PVC) film on the loss of fresh weight and water, on the development of chilling injury symptoms, and on the postharvest metabolism of carbohydrates, in arracacha tuber roots (Arracacia xanthorrhiza). The PVC film reduced the fresh weight loss and kept water content in the roots during 60-day storage period at 5 and 10ºC. PVC film in both storage temperatures inhibited the development of external and internal chilling injury symptoms. The low temperatures induced the increase of soluble sugar content and decrease of starch concentration, where the increase in soluble sugar was transient in roots stored without PVC film, and the rate of starch degradation was higher compared to the roots stored with PVC