Basal injury syndrome of Pinus needles

1986 ◽  
Vol 64 (3) ◽  
pp. 632-642 ◽  
Author(s):  
P. M. Rice ◽  
C. E. Carlson ◽  
J. J. Bromenshenk ◽  
C. C. Gordon ◽  
P. C. Tourangeau
Keyword(s):  
Air Pollution ◽  
Pinus Ponderosa ◽  
Fluoride Concentration ◽  
Scale Insect ◽  
Scale Insects ◽  
Mesophyll Cells ◽  
Injury Rates ◽  
Airborne Pollutants ◽  
Pollutant Concentrations ◽  
Longitudinal Split

Two types of macroscopic lesions, basal blister and basal necrosis, disrupting the surface tissues of Pinus needles under the fascicular sheath, are described in detail for the first time. In basal blister, hypertrophy and hyperplasia o mesophyll parenchyma cause an oval to elliptical bulge on the needle surface with a longitudinal split of the epidermal and hypodermal layers. In basal necrosis, the epidermal and hypodermal cells become necrotic, while the underlying mesophyll cells undergo structural disorganization. The causal agents are not known but in this study scale insects and deposition of airborne pollutants were associated with basal injury syndrome. The occurrence of basal injury symptoms increased with the age of the needles and the ambient concentration of acid rain precursors. The sulfur and fluoride concentration of the fascicular sheath also increased with the age of the foliage and the ambient pollutant concentrations. Basal injury on sites remote from strong sources of air pollution was significantly correlated with fascicular sheath sulfur concentrations within age-classes of older foliage. These remote site correlations occurred at basal injury rates and fascicular sheath sulfur concentrations lower than those typical of acutely impacted sites near strong sources of air pollution, and thus may represent a chronic impact resulting from acid deposition over wide geographic regions. A soft-bodied scale insect, Matsucoccus secretus Morrison, was often found under the fascicular sheath of Pinus ponderosa Dougl. ex Laws, but did not appear to be a primary cause of basal injury.

scholarly journals Design of Road-Side Barriers to Mitigate Air Pollution near Roads

2021 ◽  
Vol 11 (5) ◽  
pp. 2391
Author(s):  
Jose I. Huertas ◽  
Javier E. Aguirre ◽  
Omar D. Lopez Mejia ◽  
Cristian H. Lopez
Keyword(s):  
Fluid Dynamics ◽  
Air Pollution ◽  
Computational Fluid Dynamics ◽  
Sulfur Hexafluoride ◽  
Computational Domain ◽  
Cfd Model ◽  
Near Surface ◽  
The Road ◽  
Pollutant Concentrations ◽  
Highly Correlated

The effects of using solid barriers on the dispersion of air pollutants emitted from the traffic of vehicles on roads located over flat areas were quantified, aiming to identify the geometry that maximizes the mitigation effect of air pollution near the road at the lowest barrier cost. Toward that end, a near road Computational Fluid Dynamics (NR-CFD) model that simulates the dispersion phenomena occurring in the near-surface atmosphere (<250 m high) in a small computational domain (<1 km long), via Computational Fluid Dynamics (CFD) was used. Results from the NR-CFD model were highly correlated (R2 > 0.96) with the sulfur hexafluoride (SF6) concentrations measured by the US-National Oceanic and Atmospheric Administration (US-NOAA) in 2008 downwind a line source emission, for the case of a 6m near road solid straight barrier and for the case without any barrier. Then, the effects of different geometries, sizes, and locations were considered. Results showed that, under all barrier configurations, the normalized pollutant concentrations downwind the barrier are highly correlated (R2 > 0.86) to the concentrations observed without barrier. The best cost-effective configuration was observed with a quarter-ellipse barrier geometry with a height equivalent to 15% of the road width and located at the road edge, where the pollutant concentrations were 76% lower than the ones observed without any barrier.

scholarly journals Assessment of the Wearability of Facemasks against Air Pollution in Primary School-Aged Children in London

2020 ◽  
Vol 17 (11) ◽  
pp. 3935 ◽  
Author(s):  
Naomi R Smart ◽  
Claire J Horwell ◽  
Trevor S Smart ◽  
Karen S Galea
Keyword(s):  
Air Pollution ◽  
Primary School ◽  
Primary School Children ◽  
Perceived Fit ◽  
Major Health Problem ◽  
Airborne Pollutants ◽  
Main Complaint ◽  
Running Activity ◽  
The Face ◽  
The Uk

Air pollution is a major health problem and children are particularly vulnerable to the adverse effects. Facemasks are one form of protection but, to be effective, they need to filter out airborne pollutants, fit the face well and be wearable. In this pilot study, we assess the perceived wearability of three facemasks (Vogmask, TuHao and ReSpimask) marketed in the UK as being designed to protect children against exposure to air pollution. Twenty-four primary school children wore each facemask during a standardised walking and running activity. After each activity, the children were asked to rate facemask wearability in terms of parameters, such as perceived comfort, hotness, breathability and fit. At the end of the trial, the children compared and identified their preferred facemask. The main complaint about the facemasks was the children’s faces being too hot. The ReSpimask was most frequently reported as being perceived to be the hardest to breathe through. The TuHao facemask was the only adjustable strap mask assessed but was reported to be difficult to adjust. Facemasks with a nose clip were frequently rated highest for fit (TuHao and Vogmask). The patterned, cloth fabric Vogmask had significantly higher ratings for appearance and perceived fit. The results show children’s perceptions of facemasks are highly affected by the facemask’s design, hotness and perceived breathability. By making children’s facemasks more appealing, breathable, cooler and improving their fit, wearability may be improved.

Towards the identification of the scale insects (Hemiptera: Coccomorpha) of continental Africa: 1. Identification of the families

Zootaxa ◽  
2021 ◽  
Vol 5052 (2) ◽  
pp. 1-40
Author(s):  
GILLIAN W. WATSON ◽  
DAVID OUVRARD
Keyword(s):  
Scale Insect ◽  
Economic Importance ◽  
Scale Insects ◽  
Insect Fauna ◽  
Adult Females ◽  
Plant Parasites ◽  
Plant Sap

Scale insects (Hemiptera: Sternorrhyncha: Coccomorpha) are obligate plant parasites feeding on plant sap; some are damaging pests in agriculture, horticulture and forestry. Despite their economic importance, the scale insects found in continental Africa have not been extensively studied and the keys for identifying them are incomplete and scattered through the literature in several languages. The aim of this study is to improve our understanding of the African scale insect fauna. As a first step towards their identification, we provide a key to the 23 families currently known from continental Africa, based on slide-mounted adult females, covering Aclerdidae, Asterolecaniidae, Cerococcidae, Coccidae, Conchaspididae, Dactylopiidae, Diaspididae, Eriococcidae, Halimococcidae, Kermesidae, Kerriidae, Kuwaniidae, Lecanodiaspididae, Margarodidae, Matsucoccidae, Micrococcidae, Monophlebidae, Ortheziidae, Phoenicococcidae, Pseudococcidae, Putoidae, Rhizoecidae and Stictococcidae.  

Neolecanium cornuparvum (Magnolia scale).

2021 ◽  
Author(s):  
Angela Whittaker
Keyword(s):  
Endangered Species ◽  
Adverse Effects ◽  
Native Species ◽  
Scale Insect ◽  
Scale Insects ◽  
Southern Ontario ◽  
Eastern Usa

Abstract Magnolia scale, Neolecanium cornuparvum, is a scale insect that is native to the eastern USA, where it is a widely distributed pest of wild and ornamental Magnolia in landscapes and nurseries. In general, non-native species of Magnolia tend to be more susceptible to attack than native US species. N. cornuparvum has also been reported on Wisteria in Connecticut. The genus and species were first reported from Canada from a specimen of N. cornuparvum collected in 1998 in southern Ontario, where the insect is now an established pest of Magnolia, having probably been spread via the plant trade. An infestation of scale insects believed to be N. cornuparvum was first observed in Hawaii on Sesbania tomentosa on Kauai in August 2004; it had significant adverse effects on this endangered species.

scholarly journals Analysis of Temporal Variations of Air Pollutant Concentrations in Ogoni Area, Niger Delta Region, Nigeria

2021 ◽  
pp. 63-73
Author(s):  
B. Yorkor ◽  
T. G. Leton ◽  
J. N. Ugbebor
Keyword(s):  
Air Pollution ◽  
Temporal Variability ◽  
Niger Delta ◽  
Air Pollutants ◽  
Temporal Variations ◽  
Time Of Day ◽  
Air Pollutant ◽  
Pollutant Concentrations ◽  
Hourly Data ◽  
Air Pollutant Concentrations

This study investigated the temporal variations of air pollutant concentrations in Ogoni area, Niger Delta, Nigeria. The study used hourly data measured over 8 hours for 12 months at selected locations within the area. The analyses were based on time series and time variations techniques in Openair packages of R programming software. The variations of air pollutant concentrations by time of day and days of week were simulated. Hours of the day, days of the week and monthly variations were graphically simulated. Variations in the mean concentrations of air pollutants by time were determined at 95 % confidence intervals. Sulphur dioxide (SO2), Nitrogen dioxide (NO2), ground level Ozone (O3) and fine particulate matter (PM2.5) concentrations exceeded permissible standards. Air pollutant concentrations showed increase in January, February, November and December compared to other months. Simulation showed that air pollutants varied significantly by hours-of-the-day and days-of-the-week and months-of-the-year. Analysis of temporal variability revealed that air pollutant concentrations increased during weekdays and decreased during weekends. The temporal variability of air pollutants in Ogoni area showed that anthropogenic activities were the main sources of air pollution in the area, therefore further studies are required to determine air pollutant dispersion pattern and evaluation the potential sources of air pollution in the area.

scholarly journals Associations of Ambient Air Pollutants and Meteorological Factors With COVID-19 Transmission in 31 Chinese Provinces: A Time Series Study

2021 ◽  
Vol 58 ◽  
pp. 004695802110602
Author(s):  
Han Cao ◽  
Bingxiao Li ◽  
Tianlun Gu ◽  
Xiaohui Liu ◽  
Kai Meng ◽  
...  
Keyword(s):  
Air Pollution ◽  
Relative Humidity ◽  
Wind Velocity ◽  
Air Pollutants ◽  
Meteorological Factors ◽  
Meta Analysis ◽  
Ambient Air ◽  
Air Pollutant ◽  
Pollutant Concentrations ◽  
Air Pollutant Concentrations

Evidence regarding the effects of environmental factors on COVID-19 transmission is mixed. We aimed to explore the associations of air pollutants and meteorological factors with COVID-19 confirmed cases during the outbreak period throughout China. The number of COVID-19 confirmed cases, air pollutant concentrations, and meteorological factors in China from January 25 to February 29, 2020, (36 days) were extracted from authoritative electronic databases. The associations were estimated for a single-day lag as well as moving averages lag using generalized additive mixed models. Region-specific analyses and meta-analysis were conducted in 5 selected regions from the north to south of China with diverse air pollution levels and weather conditions and sufficient sample size. Nonlinear concentration–response analyses were performed. An increase of each interquartile range in PM2.5, PM10, SO2, NO2, O3, and CO at lag4 corresponded to 1.40 (1.37–1.43), 1.35 (1.32–1.37), 1.01 (1.00–1.02), 1.08 (1.07–1.10), 1.28 (1.27–1.29), and 1.26 (1.24–1.28) ORs of daily new cases, respectively. For 1°C, 1%, and 1 m/s increase in temperature, relative humidity, and wind velocity, the ORs were 0.97 (0.97–0.98), 0.96 (0.96–0.97), and 0.94 (0.92–0.95), respectively. The estimates of PM2.5, PM10, NO2, and all meteorological factors remained significantly after meta-analysis for the five selected regions. The concentration–response relationships showed that higher concentrations of air pollutants and lower meteorological factors were associated with daily new cases increasing. Higher air pollutant concentrations and lower temperature, relative humidity and wind velocity may favor COVID-19 transmission. Controlling ambient air pollution, especially for PM2.5, PM10, NO2, may be an important component of reducing risk of COVID-19 infection. In addition, as winter months are arriving in China, the meteorological factors may play a negative role in prevention. Therefore, it is significant to implement the public health control measures persistently in case another possible pandemic.

scholarly journals A foehn-induced haze front in Beijing: observations and implications

2020 ◽  
Author(s):  
Ju Li ◽  
Zhaobin Sun ◽  
Donald H. Lenschow ◽  
Mingyu Zhou ◽  
Youjun Dou ◽  
...  
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Surface Wind ◽  
Layer Growth ◽  
Air Mass ◽  
Pollutant Concentrations ◽  
Clean Air ◽  
Particulate Concentration ◽  
Weak Pressure Gradient ◽  
Bth Region

Abstract. Despite frequent foehns in the Beijing–Tianjin–Hebei (BTH) region, there are only a few studies of their effects on air pollution in this region, or elsewhere. Here, we discuss a foehn-induced haze front (HF) event using observational data to document its structure and evolution. Using a dense network of comprehensive measurements in the BTH region, our analyses indicate that the foehn played an important role in the formation of the HF with significant impacts on air pollution. Northerly warm–dry foehn winds, with low particulate concentration in the northern area, collided with a cold–wet polluted air mass to the south and formed an HF in the urban area. The HF, which is associated with a surface wind convergence line and distinct contrasts of temperatures, humidity and pollutant concentrations, resulted in an explosive growth of particulate concentration. As the plains-mountain wind circulation was overpowered by the foehn, a weak pressure gradient due to the different air densities between air masses was the main factor forcing advances of the polluted air mass into the clean air mass, resulting in severe air pollution over the main urban areas. Our results show that the foehn can affect air pollution through two effects: direct wind transport of air pollutants, and altering the air mass properties to inhibit boundary-layer growth and thus indirectly aggravating air pollution. This study highlights the need to further investigate the foehn and its impacts on air pollution in the BTH region.

scholarly journals Non-indigenous scale insects on ornamental plants in Bulgaria and China: A survey

2017 ◽  
Vol 19 (2) ◽  
pp. 114 ◽  
Author(s):  
K. Trencheva ◽  
G. Trenchev ◽  
R. Tomov ◽  
S.-A. Wu
Keyword(s):  
Host Plants ◽  
Ornamental Plants ◽  
Scale Insect ◽  
Scale Insects ◽  
Insect Species ◽  
First Report ◽  
The Family

A preliminary list of non-indigenous scale insect species on ornamental plants in Bulgaria and China is presented. The sampling was done between April and November, 2009, in the framework of the project “Invasive scale insects on ornamental plants in Bulgaria and China”. The insects were collected in nurseries, parks, gardens, botanical collections and greenhouses. Representatives from four families have been identified in Bulgaria, the most numerous of which are the Diaspididae (eight species), Coccidae (four species), Pseudococcidae (two species) and Margarodidae (one species). Three species of non-indigenous scale insects associated with ornamental plants were collected in China, all belonging to the family Pseudococcidae. A list of alien scale insect species on ornamental plants is given, including the sampling sites, host plants on which they were found, origin and first report in both countries.

Scale insect genus names and their families in the scale insects (Hemiptera: Sternorrhyncha: Coccomorpha), a supplement

Zootaxa ◽  
2020 ◽  
Vol 4755 (1) ◽  
pp. 197-200
Author(s):  
DOUGLAS J. WILLIAMS ◽  
BARBARA D. DENNO
Keyword(s):  
Type Species ◽  
Scale Insect ◽  
Scale Insects ◽  
Comprehensive List

A list of genus names in the scale insects published between 2014 and the end of 2019 is provided; it follows on from an earlier comprehensive list of the names published between 1758 and the end of 2013. Each genus name and its type species are assigned to one of the 53 scale insect families now recognised. 

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