Unexposed control subjects (n = 106), power distributing and office workers (n = 122), and manganese (Mn)-exposed ferroalloy smelter workers (n = 95) were recruited to the control, low and high groups, respectively. Mn concentrations in saliva, plasma, erythrocytes, urine and hair were significantly higher in both exposure groups than in the controls. The Fe concentration in plasma and erythrocytes, however, was significantly lower in Mn-exposed workers than in controls. The airborne Mn levels were significantly associated with Mn/Fe ratio (MIR) of erythrocytes (eMIR) (r = 0.77, p < 0.01) and plasma (pMIR) (r = 0.70, p < 0.01). The results suggest that the MIR may serve as a useful biomarker to distinguish Mn-exposed workers from the unexposed, control population.
A biomarker for detection of early onset neurobehavioral alterations in manganism remains unknown. The purpose of this study was to use a neurobehavioral test battery to identify subtle changes in Mn-induced motor and memory dysfunction and to relate the quantifiable neurological dysfunction to an established Mn-exposure index such as blood manganese–iron ratio (MIR). A total of 323 subjects were recruited to control (n = 106), low-exposure (122), and high-exposure (95) groups. The test battery consisted of standard testing procedures including the nine-hole and groove-type steadiness tester, Benton visual retention test, and Purdue pegboard coordination test. No significant health problems or clinically diagnosed neurological dysfunctions were observed. Benton test did not reveal any abnormal memory deficits among Mn-exposed smelters, nor did the groove and nine-hole tests detect any abnormality in dynamic and static steadiness in tested subjects. Purdue pegboard test showed a remarkable age-related decline in fine movement coordination among all study participants regardless of the Mn-exposure condition. Mn exposure significantly exacerbated this age-related deterioration. Statistical modeling revealed that the plasma and erythrocyte MIR (i.e., pMIR and eMIR, respectively) were associated with Purdue pegboard scores. Among all subjects whose MIR were above the cut-off value (COV), pMIR was significantly correlated with pegboard scores (r = −0.261, p = 0.002), whereas for those subjects over the age of 40, the eMIR, but not pMIR, was associated with declined pegboard performance (r = −0.219, p = 0.069). When both factors were taken into account (i.e., age > 40 and MIR > the COV), only pMIR was inversely associated with pegboard scores. Combining their usefulness in Mn-exposure assessment, we recommend that the blood Mn–Fe ratio may serve as a reasonable biomarker not only for assessment of Mn exposure but also for health risk assessment.
Stigmaeidae is one of the most studied mite families in Acarology, with the number of described species increasing by 44 percent in the last twenty years. To summarize the taxonomic and biological research in this family we compiled a catalogue with annotated information to nomenclature, synonymies, type localities, type depositories, host/habitat, feeding habits (if applicable) and distribution of 577 species in 34 genera (up to 31 July 2016). We also provide an overview of the main revisions and reviews. To facilitate future taxonomic research we present a pictorial key to genera. The following nomenclature changes are made: Raphignathus siculus var. lapponica Trägårdh, 1910 and Wooderia philippica Rimando & Corpuz-Raros, 1997 transferred to Eustigmaeus Berlese, Mullederia makilingae Rimando & Corpuz-Raros, 1996 transferred to Indostigmaeus Gupta & Ghosh.
The diamondback moth, Plutella xylostella is a cosmopolitan pest that has evolved resistance to all classes of insecticide, and costs the world economy an estimated US $4-5 billion annually. We analyse patterns of variation among 532 P. xylostella genomes, representing a worldwide sample of 114 populations. We find evidence that suggests South America is the geographical area of origin of this species, challenging earlier hypotheses of an Old-World origin. Our analysis indicates that Plutella xylostella has experienced three major expansions across the world, mainly facilitated by European colonization and global trade. We identify genomic signatures of selection in genes related to metabolic and signaling pathways that could be evidence of environmental adaptation. This evolutionary history of P. xylostella provides insights into transoceanic movements that have enabled it to become a worldwide pest.
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