June October Research Articles

Convective Coupling in Tropical-Depression-Type Waves. Part I: Rainfall Characteristics and Moisture Structure

AbstractTropical-depression (TD)-type waves are synoptic-scale disturbances embedded with deep convection over the western North Pacific. Studies of these disturbances began over six decades ago; however, some properties of these disturbances remain vague, e.g., the coupling mechanism between the deep convection and the waves. This two-part study aims to examine the rainfall progression in TD-type disturbances and associated tropospheric moisture controlling convective rainfall. Part I investigates the rainfall and moisture characteristics of TD-type waves using TRMM-derived rainfall products and the ERA-Interim data during the period of June–October 1998–2013. The rainfall features a north–south asymmetrical pattern with respect to a TD-type disturbance, with enhanced convective and stratiform rainfall occurring in the southern portion. Along with the northwestward propagation, deep convective and stratiform rainfall occur in phase with the TD-type disturbance without significant preceding shallow convective rainfall. Following the deepest convection, shallow convective rainfall increases in the anomalous southerlies. Such a rainfall progression differs from the paradigm from shallow to deep convection, then to stratiform rainfall, which is suggested in other convectively coupled equatorial waves. The rainfall progression and the atmospheric moisture anomaly are phase locked to the TD-type disturbances such that the relative displacements change little when the disturbances propagate northwestward. The latent heat release in deep convection, which is obtained from the TRMM 3G25 dataset, superposes with a broad warm anomaly in the mid- to upper troposphere, suggesting wave growth through the generation of available potential energy from diabatic heating.

Air–Sea Interactions among Oceanic Low-Level Cloud, Sea Surface Temperature, and Atmospheric Circulation on an Intraseasonal Time Scale in the Summertime North Pacific Based on Satellite Data Analysis

AbstractLow-level cloud plays a key role in modulating air–sea interaction processes and sea surface temperature (SST) variability. The present study investigated the evolution process of oceanic low-level cloud cover (LCC) and related air–sea interaction processes on an intraseasonal time scale in the summertime (June–October) North Pacific (30°–40°N, 165°–175°E) based on satellite observational and reanalysis datasets from 2003 to 2016. The intraseasonal time scale (20–100 days) is dominant not only for the LCC, but also for LCC controlling factors, that is, SST, estimated inversion strength (EIS), and horizontal temperature advection (Tadv). To reveal the lead–lag relationship among these variables, we conducted phase composite analysis with a bandpass filter based on the intraseasonal variability (ISV) of LCC. It suggests that ISV of LCC leads to that of SST and that horizontal dry–cold advection from the poleward region leads to increasing LCC and decreasing SST. The increasing LCC corresponds to a positive relative humidity (RH) anomaly in the lower troposphere, which is due to adiabatic cooling with shallow convection, vertical moisture advection, and meridional RH advection associated with the anomalous cold Tadv. Heat budget analysis of the ocean mixed layer suggests the importance of anomalous dry–cold advection for cooling SST, not only via enhanced latent heat release but also via decreased downward shortwave radiation at the sea surface according to cloud radiative effect with a positive LCC anomaly. Determining the detailed lead–lag relationship between LCC and its controlling factor is a good approach to understand mechanisms of the local processes of both low-level cloud evolution and air–sea interaction.

Elucidating controls on cyanobacteria bloom timing and intensity via Bayesian mechanistic modeling

The adverse impacts of harmful algal blooms (HABs) are increasing worldwide. Lake Erie is a North American Great Lake highly affected by cultural eutrophication and summer cyanobacterial HABs. While phosphorus loading is a known driver of bloom size, more nuanced yet crucial questions remain. For example, it is unclear what mechanisms are primarily responsible for initiating cyanobacterial dominance and subsequent biomass accumulation. To address these questions, we develop a mechanistic model describing June–October dynamics of chlorophyll a, nitrogen, and phosphorus near the Maumee River outlet, where blooms typically initiate and are most severe. We calibrate the model to a new, geostatistically-derived dataset of daily water quality spanning 2008–2017. A Bayesian framework enables us to embed prior knowledge on system characteristics and test alternative model formulations. Overall, the best model formulation explains 42% of the variability in chlorophyll a and 83% of nitrogen, and better captures bloom timing than previous models. Our results, supported by cross validation, show that onset of the major midsummer bloom is associated with about a month of water temperatures above 20 °C (occurring 19 July to 6 August), consistent with when cyanobacteria dominance is usually reported. Decreased phytoplankton loss rate is the main factor enabling biomass accumulation, consistent with reduced zooplankton grazing on cyanobacteria. The model also shows that phosphorus limitation is most severe in August, and nitrogen limitation tends to occur in early autumn. Our results highlight the role of temperature in regulating bloom initiation and subsequent loss rates, and suggest that a 2 °C increase could lead to blooms that start about 10 days earlier and grow 23% more intense.

Seasonality of Dissolved Organic Carbon Exchange Across the Strait of Gibraltar

AbstractExchange of mass, heat, and solutes across the Strait of Gibraltar is fundamental to understand the circulation and biogeochemistry of the Mediterranean. Here we focus on the exchange of dissolved organic carbon (DOC) using data from 12 surveys conducted between 2008 and 2015. DOC exchange exhibits a marked bimodal distribution with minima in late June and late October and maxima in mid‐April and late August. This pattern is mainly due to seasonal variation of the DOC gradient between the Atlantic Surface Water entering the Mediterranean and the deep opposite flow of Mediterranean Overflow Water. The gradient is controlled by the different seasonal cycles followed by the DOC in the two layers. Annual average DOC import from the Atlantic is equivalent to 4.2 ± 1.5 Tg C yr−1, which represents 53% of the external DOC inputs and contributes to support 32% of the net heterotrophy of the Mediterranean.

Enhancing the positive effects of ecological water conservancy engineering on desert riparian forest growth in an arid basin

In arid areas, ecological water conservancy engineering influences vegetation growth by altering river flooding dynamics in addition to the depths of groundwater. However, few studies have explored how to develop the optimal floodwater and groundwater regulation strategies that take into account both ecological water supply and vegetation growth. Therefore, the aim of the present study was to propose the suitable regulation strategies by revealing that the plant growth responses to hydrological variation (i.e., the flooding and groundwater depth). Based on two growth indicators (i.e., the time-integrated normalized difference vegetation index (TINDVI) for plant canopy growth and the tree-ring chronology for trunk growth) in the middle reaches of the Tarim River, and water consumption, water discharge from ecological sluices for flooding, and groundwater depth data, after the implementation of an scheme in ecological water conservancy engineering, the ecological water transport efficiency, tree-ring chronology in Populus euphratica, and TINDVI improved by 12.4%, 5.6% and 4.2%, respectively. Notably, the tree-ring chronology increased with a decrease in water consumption. Due to a significant correlation between tree-ring chronology and TINDVI, the tree-ring chronology could be used to reconstruct the canopy growth in the case of the unavailability of monitoring data. There were significant correlations between TINDVI and groundwater depth in June–October, between tree-ring chronology and groundwater depth in October, and between water discharge from ecological sluices and vegetation growth in September. In addition, there were high correlation and sensitivity between trunk growth and water discharge (compared to groundwater depth), and between canopy growth and groundwater depth (compared to water discharge). Based on the above results, potentially sustainable groundwater depths (-2.3 to −3.7 m) and discharge water quantities (3.53–5.90 × 108 m3) and regimes were proposed that could further promote the vegetation growth.

Variability of the South Pacific Western Subtropical Mode Water and Its Relationship With ENSO During the Argo Period

AbstractThis study investigates variability of the South Pacific western subtropical mode water (SPWSTMW), its physical processes, and relationship with El Niño‐Southern Oscillation (ENSO), using a gridded Argo data product from January 2004 to September 2019. On seasonal timescale, the SPWSTMW volume shows a significant variability, which involves three periods: the formation period (June–October), the isolation period (November–February), and the dissipation period (March–May). This seasonal variability is related to seasonal fluctuation of the mixed layer depth. During the Argo period from 2004 to 2019, interannual variability of the SPWSTMW volume is tightly linked to the ENSO, increasing during El Niño periods and decreasing during La Niña periods. Further analyses indicate that ENSO‐related anomalous winds are primarily responsible for interannual variability of the SPWSTMW volume. The anomalous winds first influence the surface heat flux through evaporation and then the mixed layer depth through convection, leaving an imprint of ENSO on the SPWSTMW. This study also shows that the SPWSTMW responds differently to the central Pacific (CP) El Niño and eastern Pacific (EP) El Niño.

The New Trainee Effect in Tracheal Intubation Procedural Safety Across PICUs in North America: A Report From National Emergency Airway Registry for Children*

Tracheal intubation carries a high risk of adverse events. The current literature is unclear regarding the "New Trainee Effect" on tracheal intubation safety in the PICU. We evaluated the effect of the timing of the PICU fellow academic cycle on tracheal intubation associated events. We hypothesize 1) PICUs with pediatric critical care medicine fellowship programs have more adverse tracheal intubation associated events during the first quarter (July-September) of the academic year compared with the rest of the year and 2) tracheal intubation associated event rates and first attempt success performed by pediatric critical care medicine fellows improve through the 3-year clinical fellowship. Retrospective cohort study. Thirty-seven North American PICUs participating in National Emergency Airway Registry for Children. All patients who underwent tracheal intubations in the PICU from July 2013 to June 2017. None. The occurrence of any tracheal intubation associated events during the first quarter of the academic year (July-September) was compared with the rest in four different types of PICUs: PICUs with fellows and residents, PICUs with fellows only, PICUs with residents only, and PICUs without trainees. For the second hypothesis, tracheal intubations by critical care medicine fellows were categorized by training level and quarter for 3 years of fellowship (i.e., July-September of 1st yr pediatric critical care medicine fellowship = first quarter, October-December of 1st yr pediatric critical care medicine fellowship = second quarter, and April-June during 3rd year = 12th quarter). A total of 9,774 tracheal intubations were reported. Seven-thousand forty-seven tracheal intubations (72%) were from PICUs with fellows and residents, 525 (5%) with fellows only, 1,201 (12%) with residents only, and 1,001 (10%) with no trainees. There was no difference in the occurrence of tracheal intubation associated events in the first quarter versus the rest of the year (all PICUs: July-September 14.9% vs October-June 15.2%; p = 0.76). There was no difference between these two periods in each type of PICUs (all p ≥ 0.19). For tracheal intubations by critical care medicine fellows (n = 3,836), tracheal intubation associated events significantly decreased over the fellowship: second quarter odds ratio 0.64 (95% CI, 0.45-0.91), third quarter odds ratio 0.58 (95% CI, 0.42-0.82), and 12th quarter odds ratio 0.40 (95% CI, 0.24-0.67) using the first quarter as reference after adjusting for patient and device characteristics. First attempt success significantly improved during fellowship: second quarter odds ratio 1.39 (95% CI, 1.04-1.85), third quarter odds ratio 1.59 (95% CI, 1.20-2.09), and 12th quarter odds ratio 2.11 (95% CI, 1.42-3.14). The New Trainee Effect in tracheal intubation safety outcomes was not observed in various types of PICUs. There was a significant improvement in pediatric critical care medicine fellows' first attempt success and a significant decline in tracheal intubation associated event rates, indicating substantial skills acquisition throughout pediatric critical care medicine fellowship.

Causes of the diurnal variation observed in gamma-ray spectrum using NaI (Tl) detector

Present paper studies the γ-ray spectrum observed using NaI (Tl) scintillation detector over a year. The paper reports the presence of a distinct diurnal pattern in the total number of γ-ray counts detected by the NaI detector. The counts start decreasing after sunrise and show gradual recovery after sunset. The amplitude of this variation is quite significant ( >10%) at the observation site Tirunelveli, South India. However, further investigation based on different energy ranges reveals that the mentioned diurnal pattern is actually present only in the energies related to the terrestrial background radioactivity. The study demonstrates that the pattern is associated with the radioactivity of isotopes of radon (222Rn and 220Rn) and their daughter radionuclides. The amplitude of the diurnal variation is found to have seasonal dependence, with the lowest amplitude during June–October (∼2%), and highest in April–May months (∼14%). The dependence of the amplitude of the diurnal variation on various atmospheric parameters, namely temperature, relative humidity, and the vertical wind is examined. The observed diurnal pattern is attributed to the generation of the inversion layer. The distribution of concentration of radon and thoron progenies in an air column changes with the vertical mixing and atmospheric boundary layer (ABL), resulting in the diurnal variation of γ-rays. The observed lower amplitudes in the months of June–October may be due to the presence of downward winds restricting the radon movement to a thin layer, giving smaller amplitudes of the diurnal variation in total γ-ray flux resulting in seasonal variation.

THE EFFECT OF GINKGO BILOBA AGAINST OTOTOXIC HEARING LOSS ON ADVANCED STAGE UNDIFFERENTIATED NASOPHARYNGEAL CARCINOMA RECEIVING CISPLATIN CHEMOTHERAPY

Abstract Introduction: Undifferentiated nasopharyngeal carcinoma is the most common malignant tumor in nasopharynx, in which most patients come to a hospital in advanced stage. Cisplatin is one of the most effective widely used chemotherapy drugs for advanced stage undifferentiated nasopharyngeal carcinoma. Although it provides a successful outcome against cancer, there is serious side effect namely ototoxic hearing loss. Ginkgo biloba is a powerful antioxidant which may prevent ototoxic hearing loss. Objective: The study aims to determine the effect of ginkgo biloba against ototoxic hearing loss on advanced stage undifferentiated nasopharyngeal carcinoma receiving cisplatin chemotherapy. Methods: This study was double blind Randomized Control Trial with pre-post test design, was conducted in 22 patients with advanced stage undifferentiated nasopharyngeal carcinoma receiving cisplatin chemotherapy at the Department of Otorhinolaryngology Head and Neck Surgery dr. Moewardi Hospital Surakarta between June 1st and October 1st 2019. The subjects were allocated into control (plasebo) and treatment (80 mg Ginkgo biloba extract) groups. Hearing function was examined with pure tone audiometry, tympanometry and Distortion Product Otoacoustic Emission before and after the first, the second and the third cisplatin chemotherapy. The results of the examination of the two groups were tested using Friedman and Chi Square test. P value of <0.05 was considered significant. Results: The study subjects were mostly male (63.6%), with the age range of 40-59 years (90.9%). The baseline characteristics of the study subjects were homogeneous (p>0.05). There was a significant difference in the incidence of ototoxic hearing loss between control and treatment group after getting the second and the third chemotherapy (p=0.043 and p=0.033, respectively). Conclusion: There is a significant effect of ginkgo biloba in term of preventing ototoxic hearing loss on advanced stage undifferentiated nasopharyngeal carcinoma patients receiving cisplatin chemotherapy.

On detailed field-based observations of laterite and laterization: a study in the Paschim Medinipur lateritic upland of India

The term ‘laterite’ and the process ‘laterization’—both have raised perpetual scientific debates. The present study reviews the relevant scientific pieces of literature associated with tropical red lateritic and ferralitic soils and tries to justify them with the observations in the Paschim Medinipur Lateritic Upland. This particular area is practically the natural laboratory for observing the laterization process. The area exhibits a distinctive geomorphologic, hydrological, and climatic characteristic over an evolutionary geological setting. The favorable tropical climate, intense weathering, groundwater movement with seasons, and neo-tectonic upliftment exerts complex influences on the pedo-geomorphological distinctiveness of this area. Presence of planation surfaces, typical scarp development along the surface margins and exposure of deep lateritic profiles by basal sapping, accelerated erosion of the margin, and formation of rills and gullies with waxing slope development are worthy of being synced with available scientific understandings. The study is based on extensive field observations, profile studies, and soil sample analysis from different geomorphic units. The study reveals that the role of tectono-climatic evolution has had a massive influence on characteristics and development of the present lateritic formations. Transportation and deposition of Neogene ferruginous sediments over basin shelf region as paradeltaic formation, alternating wet (June–October), and dry (November–May) monsoonal climate with adequate rainfall and iron segregation and relative accumulation along with neo-tectonic modification are the important considerations regarding ferrugination process in the area under study. The justifications of the observed attributes of this particular tropical lateritic landscape may be used as a reference work for future scientific studies and model building processes on the same in this area as well as the other parts of the world.

Characteristics of the Z–R Relationships Observed Using Micro Rain Radar (MRR-2) over Darjeeling (27.05° N, 88.26° E): A Complex Terrain Region in the Eastern Himalayas

The relationship ( $$\varvec{Z} = \varvec{AR}^{\varvec{b}}$$ ) between radar reflectivity factor, $$\varvec{ Z }$$ and rainfall rate, $$\varvec{R }$$ is studied using the micro rain radar (MRR) observation located over Darjeeling (27.05° N, 88.26° E, 2194 m above the msl) in the foothills of the eastern Himalayan Mountains during Indian summer monsoon and post monsoon seasons (June–October) 2013. Observations from MRR are classified mainly into two types, stratiform and convective, based on the bright band and non-bright band signatures in the radar reflectivity, respectively. We have observed 12 and 7 cases for the stratiform convective rain events, respectively. In the present study MRR is operated mostly during low intensity rainfall rate (0.02–20 mm/h). During southwest monsoon season $$\varvec{Z} {-} \varvec{R }$$ relation for the stratiform and convective rainfall types are found to be $$\varvec{Z} = 272\varvec{R}^{1.78}$$ and $$\varvec{Z} = 192\varvec{R}^{1.54}$$ respectively. $$\varvec{Z} {-} \varvec{R }$$ relation for both stratiform and convective rain shows high temporal variation during different months of monsoon and post monsoon seasons. The coefficient $$\varvec{A}$$ varies between 225 and 289 for stratiform rain and between 153 and 235 for convective rain. The exponent $$\varvec{b}$$ varies between 1.4 and 2.1 for stratiform rain while between 1.2 and 1.8 for convective rain. Interestingly, we observed a distinct relation with smaller values of $$\varvec{A}$$ and $$\varvec{b}$$ for convective rain than stratiform rain over Darjeeling. The height dependence of $$\varvec{A}$$ and $$\varvec{b}$$ are also studied which is found to be very small up to ~ 1.5 km above the surface for both types of the precipitating systems.

High-resolution fully coupled atmospheric–hydrological modeling: a cross-compartment regional water and energy cycle evaluation

Abstract. The land surface and the atmospheric boundary layer are closely intertwined with respect to the exchange of water, trace gases, and energy. Nonlinear feedback and scale-dependent mechanisms are obvious by observations and theories. Modeling instead is often narrowed to single compartments of the terrestrial system or bound to traditional viewpoints of definite scientific disciplines. Coupled terrestrial hydrometeorological modeling systems attempt to overcome these limitations to achieve a better integration of the processes relevant for regional climate studies and local-area weather prediction. This study examines the ability of the hydrologically enhanced version of the Weather Research and Forecasting model (WRF-Hydro) to reproduce the regional water cycle by means of a two-way coupled approach and assesses the impact of hydrological coupling with respect to a traditional regional atmospheric model setting. It includes the observation-based calibration of the hydrological model component (offline WRF-Hydro) and a comparison of the classic WRF and the fully coupled WRF-Hydro models both with identically calibrated parameter settings for the land surface model (Noah-Multiparametrization; Noah-MP). The simulations are evaluated based on extensive observations at the Terrestrial Environmental Observatories (TERENO) Pre-Alpine Observatory for the Ammer (600 km2) and Rott (55 km2) river catchments in southern Germany, covering a 5-month period (June–October 2016). The sensitivity of seven land surface parameters is tested using the Latin-Hypercube–One-factor-At-a-Time (LH-OAT) method, and six sensitive parameters are subsequently optimized for six different subcatchments, using the model-independent Parameter Estimation and Uncertainty Analysis software (PEST). The calibration of the offline WRF-Hydro gives Nash–Sutcliffe efficiencies between 0.56 and 0.64 and volumetric efficiencies between 0.46 and 0.81 for the six subcatchments. The comparison of the classic WRF and fully coupled WRF-Hydro models, both using the calibrated parameters from the offline model, shows only tiny alterations for radiation and precipitation but considerable changes for moisture and heat fluxes. By comparison with TERENO Pre-Alpine Observatory measurements, the fully coupled model slightly outperforms the classic WRF model with respect to evapotranspiration, sensible and ground heat flux, the near-surface mixing ratio, temperature, and boundary layer profiles of air temperature. The subcatchment-based water budgets show uniformly directed variations for evapotranspiration, infiltration excess and percolation, whereas soil moisture and precipitation change randomly.

The value of rested sourveld in a communal grazing area in the Eastern Cape, South Africa

The potential for forage accumulated during periodic long rests to provide valuable winter grazing for livestock in heavily stocked communal rangelands in sourveld was assessed. In a continuously-grazed commonage at Ntshiqo in the Eastern Cape, South Africa, we measured seasonal patterns of biomass accumulation and forage quality under a short season rest (October–January), a full summer rest (October–June), and an extended year rest (June 2014–October 2015). Forage quality was expected to decline with increasing biomass accumulation. The full season rest produced twice as much (almost 1 ton ha−1) biomass than the short season rest. Up to 1.5 tons ha−1 more forage accumulated in the exclosures in the extended year rest, compared with the surrounding grazed grassland, but about 15% of the standing dry matter was lost through frost and senescence from the rested areas during winter. Forage quality (crude protein, phosphorus) declined from summer to winter and was similar in all rested and grazed areas, except for 4% higher acid detergent fibre (ADF) for the full- versus the short-summer rest. For commonage in sourveld, periodic full season rests (spring to autumn), followed by winter grazing with a protein lick and a spring burn, are recommended.

A New Index to Better Detect and Monitor Agricultural Drought in Niger Using Multisensor Remote Sensing Data

In this study, we propose a new remote sensing–based drought index, the agricultural drought condition index (ADCI), for agricultural drought monitoring in the agricultural area of Niger. It is defined as a first principal component analysis (PCA) of precipitation condition index (PCI), vegetation condition index (VCI), temperature condition index (TCI), and evapotranspiration condition index (ETCI). ADCI integrates multisource remote sensing data from Climate Hazards group Infrared Precipitation with Station (CHIRPS) and moderate resolution imaging spectro-radiometer (MODIS) and it synthesizes precipitation deficits, vegetation growth status, soil thermal stress, and crop water stress in the drought process. A series of validation tests have been implemented using a one-month standardized precipitation index (SPI-1), the crop yield and the vegetation health index (VHI) during the crop growth period (June–October) from 2003 to 2017. The results show that ADCI is not only strongly correlated with SPI-1, but also with the variation of crop yield and the VHI. When tested against VHI, the ADCI performed better than VHI. Thus, it was proven that this index is a full drought monitoring indicator and it can not only contain the meteorological drought information, but also reflect drought influence on agriculture.

Rural Glaucoma in China: Present Status and Future Directions

BACKGROUND: Glaucoma is the commonest cause of irreversible blindness worldwide. Factors associated with the development of glaucoma have been examined in several studies, but not in the Chinese rural population. The China Rural Glaucoma Cohort Study (China-RG Study) was conducted to investigate the present status of glaucoma in China. METHODS: The China-RG Study is a population-based study (June–October 2018) that included 22 rural areas from ten provinces in China and enrolled 52,041 individuals (age >6 years). Participants completed a comprehensive eye examination, including visual acuity, intraocular pressure (IOP), slit-lamp microscopy, direct ophthalmoscopy, and further investigations. Associations of demographics and medical factors with glaucoma were assessed using multiple logistic regression models. Disability (YLD) and quality-adjusted life-years (QALYs) were used to express adverse health outcomes of glaucoma; cost-effectiveness analysis was conducted to evaluate the superiority of glaucoma-screening program. FINDINGS: Overall prevalence of glaucoma was 1.6% (95% CI 1.52–1.77%); 58.2%, and 19.8% had primary angle-closure glaucoma (PACG) or primary open-angle glaucoma (POAG), respectively. Increasing age, history of cerebral infarction, marital status, location, and family history of glaucoma were significant risk factors for both PACG and POAG. Cost–benefit analysis indicated savings of approximately 286,56.57 million yuan in direct medical expenses nationwide by adopting the proposed screening mode. INTERPRETATION: Glaucoma should be included in chronic disease-management programs in China for long-term care and continuous management of high-risk cases. The scope and inclusions of basic public health services should be expanded, especially to include ophthalmic diseases. FUNDING STATEMENT: This research was supported by the National Natural Science Foundation of China (grant no. 81830026) and the Natural Science Foundation of Tianjin (grant no. 18ZXDBSY00030) DECLARATION OF INTERESTS: The authors declare there are no competing interests. ETHICS APPROVAL STATEMENT: Ethics approval for study conduct was obtained from the institutional ethics committee of Tianjin Medical University General Hospital; all participants provided written informed consent prior to study participation.

Comparing stability in random forest models to map Northern Great Plains plant communities in pastures occupied by prairie dogs using Pleiades imagery

Abstract. Black-tailed prairie dogs (Cynomys ludovicianus) have been described as a keystone species and are important for grassland conservation, yet many concerns exist over the impact of prairie dogs on plant biomass production and consequently livestock production. The ability to map plant communities in pastures colonized by prairie dogs can provide land managers with an opportunity to optimize rangeland production while balancing conservation goals. The aim of this study was to test the ability of random forest (RF) models to classify five plant communities located on and off prairie dog towns in mixed-grass prairie landscapes of north central South Dakota, assess the stability of RF models among different years, and determine the utility of utilizing remote sensing techniques to identify prairie dog colony extent. During 2015 and 2016, Pleiades satellites were tasked to image the study site for a total of five monthly collections each summer (June–October). Training polygons were mapped in 2016 for the five plant communities and used to train RF models. Both the 2015 and 2016 RF models had low (1 %) out-of-bag error rates. However, comparisons between the predicted plant community maps using the 2015 imagery and one created with the 2016 imagery indicate over 32.9 % of pixels changed plant community class between 2015 and 2016. The results show that while RF models may predict with a high degree of accuracy, overlap of plant communities and interannual differences in rainfall may cause instability in fitted models. A final RF model combining both 2015 and 2016 data yielded the lowest error rates and was also highly accurate in determining prairie dog colony boundaries.

Household Food Insecurity Predicts Childhood Undernutrition: A Cross-Sectional Study in West Oromia (Ethiopia).

Background Despite mixed reports, food insecurity emerges as a predictor of nutritional status, assumably limiting the quantity and quality of dietary intake. In Ethiopia, the prevalence of childhood undernutrition and food insecurity is highly pronounced. However, whether household food insecurity predicts undernutrition in children was not yet well established. Thus, the aim of the present study was to identify the link between household food access and undernutrition in children aged 6–23 months in West Oromia zones, Ethiopia. Methods A cross-sectional study was conducted on a sample of 525 households during June–October 2016. Food access was measured as Household Food Insecurity Access Scale. Semistructured interviewer-administered questionnaires were employed to collect data on sociodemographics, child health, child dietary practices, household food security, and anthropometrics. The height and weight of children aged 6–23 months in each household were measured. Multivariate logistic regression models were constructed to assess the association between household food insecurity and child nutritional status measured from undernutrition indicators. Results Overall, more than two-thirds (69%) of households were classified as food insecure (had insufficient access to adequate food), with a mean (SD) household food access score of 7.9 (7.7). The respective prevalence of mild and moderate food-insecure households was 56.6% and 12.4%. Higher proportions of children in food-insecure households were stunted (41.8% vs. 15.5%), underweight (22.0% vs. 6.1%), and wasted (14.9% vs. 6.1%). Overall, the prevalence of child undernutrition was 21.3% in the target population, with 16.2% stunted, 6.9% underweight, and 6.3% wasted. The present finding shows food-secure households were 54% protective (OR: 0.46, 95% CI: 0.25–0.84) for child undernutrition. Compared to children in food-secure households, children who were reportedly living in moderately food-insecure households were over twice more likely stunted (OR: 2.09, 95% CI: 1.02–4.28) and over 4 times more likely underweight (OR: 4.73, 95% CI: 1.81–12.35). However, household food insecurity was not a correlate for acute malnutrition (wasting) in children. Conclusions The prevalence of household's food insecurity situation is very common and more pronounced among households with undernourished children aged 6–23 months in Ethiopia. The analysis of this work shows that moderately food-insecure households are a salient predictor for composite undernutrition, stunting, and underweight, but not for wasting. Thus, this finding informs the need for multisectoral strategies and policies to combat household's food insecurity and multiple forms of child undernutrition, beyond the socioeconomic wellbeing.

Contribution of nitrate-nitrogen concentration in groundwater to stream water in an agricultural head watershed

This study characterized nitrate-nitrogen (NO3–N) concentrations in groundwater and stream water in an agricultural head watershed in South Korea and identified the pollution load of NO3–N as a result of the groundwater entering streams using field surveys, analyses of chemical constituents, and numerical modeling. The mean NO3–N concentration in groundwater was 7.373 mg/L, which is approximately 1.9 times higher than concentrations found in stream water. The groundwater and stream water samples belonged to the Ca–HCO3 type. The concentration of NO3–N in groundwater tended to increase in the lowland areas downstream. There was seasonal variations of NO3–N in both the groundwater and stream water samples, with increases in concentration during the dry season (January–April) and decreases during the wet season (June–October). The NO3–N load in stream water to that in groundwater (R) was higher during the wet season (September) than the dry season (March), with R distinctly increasing in upstream areas relative to downstream areas, indicating that during the wet season, a large amount of NO3–N is introduced into stream water from groundwater. By analyzing the relationship between groundwater and stream water and through NO3–N transport modeling, it was revealed that in the watershed, the nitrate-N load in stream water is greatly augmented by inputs from groundwater, particularly in the middle and downstream areas.

Ultra-clean and smoky marine boundary layers frequently occur in the same season over the southeast Atlantic

Abstract. We study 41 d with daily median surface accumulation mode aerosol particle concentrations below 50 cm−3 (ultra-clean conditions) observed at Ascension Island (ASI; 7.9∘ S, 14.4∘ W) between June 2016 and October 2017 as part of the Layered Atlantic Smoke Interactions with Clouds (LASIC) campaign. Interestingly, these days occur during a period of great relevance for aerosol–cloud–radiation interactions, the southeast Atlantic (SEATL) biomass-burning season (approximately June–October). That means that these critical months can feature both the highest surface aerosol numbers, from smoke intrusion into the marine boundary layer, as well as the lowest. While carbon monoxide and refractory black carbon concentrations on ultra-clean days do not approach those on days with heavy smoke, they also frequently exceed background concentrations calculated in the non-burning season from December 2016 to April 2017. This is evidence that even what become ultra-clean boundary layers can make contact with and entrain from an overlying SEATL smoke layer before undergoing a process of rapid aerosol removal. Because many ultra-clean and polluted boundary layers observed at Ascension Island during the biomass burning season follow similar isobaric back trajectories, the variability in this entrainment is likely more closely tied to the variability in the overlying smoke rather than large-scale horizontal circulation through the boundary layer. Since exceptionally low accumulation mode aerosol numbers at ASI do not necessarily indicate the relative lack of other trace pollutants, this suggests the importance of regional variations in what constitutes an “ultra-clean” marine boundary layer. Finally, surface drizzle rates, frequencies and accumulation – as well as retrievals of liquid water path – all consistently tend toward higher values on ultra-clean days. This implicates enhanced coalescence scavenging in low clouds as the key driver of ultra-clean events in the southeast Atlantic marine boundary layer. These enhancements occur against and are likely mediated by the backdrop of a seasonal increase in daily mean cloud fraction and daily median liquid water path over ASI, peaking in September and October in both LASIC years. Therefore the seasonality in ultra-clean day occurrence seems directly linked to the seasonality in SEATL cloud properties. These results highlight the importance of two-way aerosol–cloud interactions in the region.

The community composition variation of Russulaceae associated with the Quercus mongolica forest during the growing season at Wudalianchi City, China.

BackgroundMost species of the Russulaceae are ectomycorrhizal (ECM) fungi, which are widely distributed in different types of forest ecology and drive important ecological and economic functions. Little is known about the composition variation of the Russulaceae fungal community aboveground and in the root and soil during the growing season (June–October) from a Quercus mongolica forest. In this study, we investigated the changes in the composition of the Russulaceae during the growing season of this type of forest in Wudalianchi City, China.MethodsTo achieve this, the Sanger sequencing method was used to identify the Russulaceae aboveground, and the high-throughput sequencing method was used to analyze the species composition of the Russulaceae in the root and soil. Moreover, we used the Pearson correlation analysis, the redundancy analysis and the multivariate linear regression analysis to analyze which factors significantly affected the composition and distribution of the Russulaceae fungal community.ResultsA total of 56 species of Russulaceae were detected in the Q. mongolica forest, which included 48 species of Russula, seven species of Lactarius, and one species of Lactifluus. Russula was the dominant group. During the growing season, the sporocarps of Russula appeared earlier than those of Lactarius. The number of species aboveground exhibited a decrease after the increase and were significantly affected by the average monthly air temperature (r = −0.822, p = 0.045), average monthly relative humidity (r = −0.826, p = 0.043), monthly rainfall (r = 0.850, p = 0.032), soil moisture (r = 0.841, p = 0.036) and soil organic matter (r = 0.911, p = 0.012). In the roots and soils under the Q. mongolica forest, the number of species did not show an apparent trend. The number of species from the roots was the largest in September and the lowest in August, while those from the soils were the largest in October and the lowest in June. Both were significantly affected by the average monthly air temperature (r2 = 0.6083, p = 0.040) and monthly rainfall (r2 = 0.6354, p = 0.039). Moreover, the relative abundance of Russula and Lactarius in the roots and soils showed a linear correlation with the relative abundance of the other fungal genera.