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The main objective of this study was to investigate the effects of task execution variables on the value and point of application of the resultant vertical ground reaction force acting on the foot sole during squat lifting. This can be of particular importance since it may help to recognize the roles of the foot sole parts in bearing the support force during industrial and labor lifting activities. Twelve healthy men lifted a box with 4, 8 and 12 kg masses at fast and slow speeds. Ground reaction force and center of pressure were measured using two parallel Kistler force-plates. In addition, a Vicon system and a 3D linked segment model were used to define the movement pattern. Significant increases resulted for the peak vertical ground reaction force with the increases in the lift speed (P < 0.05) and box weight (P < 0.05). As well a significant increase resulted for the range of center of pressure location with the increase in the box weight (P < 0.05). Moreover, significant interactions (P < 0.05) between the lift speed and box weight were detected. The front and rear parts of the foot had the most important roles in bearing the support force during the beginning and final phases of movement, respectively. Finally, it was concluded that the value and point of application of vertical ground reaction force are seemingly dependent on the momentum of the subject plus box., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objectives: The main objective of this study has been qualitative investigation of the effects of external loading on the lumbar extension moment during squat lifting. Findings of this study may allow to determine the factor with the most considerable effect on the lumbar extension moment and may help determine the lumbar spine risk factors at temporo-spatial coordination during squat lifting., Material and Methods: Twelve healthy men volunteered to perform slow and fast squat lifting of a box of varied mass (4 kg, 8 kg and 12 kg). The eight-channel electromyography was applied to detect the activities of abdominal (rectus abdominis and external oblique) and lower back muscles (iliocostalis lumborum and multifidus). The lumbar extension moment was calculated using 3D linked segment model. Ground reaction forces and kinematic data were recorded using a Vicon system with 2 parallel Kistler force-plates., Results: Significant increases (both p-values < 0.05) were detected for the peak lumbar extension moment with increases in the lift speed and box weight. Moreover, a significant interaction (p = 0) was detected between the lift speed and box weight. Furthermore, insignificant differences (all p-values > 0.05) were detected between the lumbar angles related to the lower trunk muscles peak activities and lumbar angle related to the peak lumbar extension moment in most of the lifts., Conclusions: According to the findings, the inertial force of the lifted box is the most important factor that affects the lumbar extension moment during squat lifting. Moreover, critical lumbar angles are seemingly those ones in which the lifted box reaches the peak acceleration. Int J Occup Med Environ Health 2017;30(4):665-679., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

Several viral diseases are responsible for significant economic losses in commercial cucurbit production worldwide. During a survey conducted in July 2002 in cucurbit growing areas in southern Iran, vein-clearing symptoms and leaf chlorosis on older leaves were observed on a cucumber plant near Jiroft (Kerman Province). These symptoms were similar to those caused by Cucumber vein yellowing virus (CVYV, genus Ipomovirus, family Potyviridae), a virus first described in Israel (1) and now widespread in cucurbit crops in the Middle East and Mediterranean Regions (2). The identification of CVYV was established through differential host range reaction and immunosorbent electron microscopy (IEM) experiments. Typical vein-clearing symptoms were observed following mechanical inoculation of cucumber and melon plantlets, but no symptoms were observed in Chenopodium quinoa, C. amaranticolor, Nicotiana tabacum, or Vigna sinensis. Numerous, slightly flexuous, elongated virus particles were observed in infected plant extracts. The particles were decorated by a polyclonal antiserum raised against a Sudanese isolate of CVYV. To confirm CVYV identification, total RNA extracts (TRI-Reagent, Sigma Chemical, St. Louis, MO) were obtained from the original cucumber sample. Reverse transcription-polymerase chain reactions (RT-PCR) were carried out using CVYV-specific primers CVYV-CP-5': 5'-GCTTCTGGTTCTCAAGTGGA-3' and CVYV-CP-3': 5'-GATGCATCAGTTGTCAGATG-3' designed according to the partial sequence of the coat protein gene of CVYV-Isr (GenBank Accession No. AF233429) (2). A 540-bp fragment corresponding to the central region of CVYV coat protein was obtained from extracts of infected plants but not from healthy plant extracts. Additional watermelon (n = 6) and melon (n = 4) leaf samples collected from plants growing in the same farm were tested for the presence of CVYV using RT-PCR. All samples reacted positively for CVYV. However, a sample of Citrullus colocynthis, a wild relative of watermelon growing nearby, was negative. CVYV was not detected using RT-PCR in 123 additional cucurbit samples collected from the eastern and central regions of Iran during a survey conducted in 2002. To our knowledge, this is the first report of the occurrence of CVYV in Iran. Additional surveys in southern regions where Bemisia tabaci, the vector of CVYV, is abundant are required to better estimate the prevalence of this virus in cucurbit crops in Iran. References: (1) S. Cohen and F. E. Nitzany. Phytopathol. Mediterr. 1:44, 1960 (2) H. Lecoq et al. J. Gen. Virol. 81:2289, 2000.

A survey was conducted from 2001 to 2004 in the major cucurbit-growing areas in Iran to reassess the relative incidence of cucurbit viruses. Severe yellowing symptoms were observed frequently on older leaves of cucurbit plants in various regions in outdoor crops, suggesting the presence of Cucurbit aphid-borne yellows virus (CABYV, genus Polerovirus, family Luteoviridae) (1,2). Leaf samples (n = 1019) were collected from plants of melon (Cucumis melo L.), cucumber (C. sativus L.), squash (Cucurbita sp.), and watermelon (Citrullus lanatus L.) showing various virus-like symptoms (mosaic, leaf deformation, yellowing). All samples, collected from 15 provinces, were screened for the presence of CABYV by double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) with IgGs and alkaline phosphatase-conjugated IgGs against a CABYV reference isolate (1). Of the 1,019 samples tested, 471 were positive for CABYV using DAS-ELISA. Some of the positive samples had typical severe yellowing symptoms while symptoms in other samples were masked by mosaic or leaf deformations caused by other viruses frequently found in mixed infections (data not shown). During the entire survey, CABYV was detected by DAS-ELISA in 201 of 503 melon samples, 72 of 129 cucumber samples, 158 of 249 squash samples, and 40 of 138 watermelon samples. These results indicate that CABYV is widely distributed on four cucurbit species in the major growing areas of Iran. In order to confirm CABYV identification, total RNA extracts (TRI-Reagent, Sigma Chemical, St Louis, MO) were obtained from 25 samples that were positive using DAS-ELISA originating from Khorasan (n = 4), Esfahan (n = 6), Teheran (n = 3), Hormozgan (n = 4), Azerbaiejan-E-Sharqi (n = 4), and Kerman (n = 4). Reverse transcription-polymerase chain reactions (RT-PCR) were carried out using forward (5'-CGCGTGGTTGTGG-TCAACCC-3') and reverse (5'-CCYGCAACCGAGGAAGATCC-3') primers designed in conserved regions of the coat protein gene according to the sequence of a CABYV reference isolate (3) and three other unpublished CABYV sequences. RT-PCR experiments yielded an expected 479-bp product similar to the fragment amplified with extracts from the reference isolate. No amplification of the product occurred from healthy plant extracts. To our knowledge, this is the first report of the occurrence of CABYV in Iran on various cucurbit species. The high frequency (46.2%) with which CABYV was detected in the samples assayed indicates that this virus is one of the most common virus infecting cucurbits in Iran. References: (1) H. Lecoq et al. Plant Pathol. 41:749, 1992 (2) M. A. Mayo and C. J. D'Arcy. Page 15 in: The Luteoviridae. H. G. Smith and H. Barker, eds. CAB International Mycological Institute, Wallingford, UK, 1999. (3) H. Guilley et al. Virology 202:1012, 1994.