Engineer Research and Development Center - U.S. Army
Recent publications
A prior multigenerational perfluorooctane sulfonic acid (PFOS) exposure investigation in zebrafish reported adverse effects at 0.734 µg/L, among the lowest aquatic effect levels for PFOS reported to date. The present three-generation PFOS exposure quantified survival, growth, reproduction, and vitellogenin (VTG; egg yolk protein) responses in zebrafish, incorporating experimental design and procedural improvements relative to the earlier study. Exposures targeting 0.1, 0.6, 3.2, 20, and 100 µg/L in parental (P) and first filial (F1) generations lasted for 180 days post fertilization (dpf) and the second filial generation (F2) through 16 dpf. Survival decreased significantly in P and F2 generation exposures, but not in F1, at the highest PFOS treatment (100 µg/L nominal, 94-205 µg/L, measured). Significant adverse effects on body weight and length were infrequent, of low magnitude, and occurred predominantly at the highest exposure treatment. Finally, PFOS had no significant effects on P or F1 egg production and survival or whole-body VTG levels in P or F1 male fish. Overall, the predominance and magnitude of adverse PFOS effects at <1 µg/L reported in prior research were largely nonrepeatable in the present study. In contrast, the present study indicated a threshold for ecologically relevant adverse effects in zebrafish at 117 µg/L (SE 8 µg/L, n = 10) for survival and 47 µg/L (SE 11 µg/L, n = 19) for all statistically significant negative effects observed.
The Mississippi River is host to multiple species of invasive carp, including bighead, silver, and black carp, which have been linked to negative ecological impacts upon introduction to a waterbody. Most of the rivers emptying into the Gulf of Mexico are hydrologically separated from the Mississippi River by seawater and have historically been considered safe from an invasion of carp attempting to traverse coastal waters due to their intolerance of seawater salinity levels. However, there is growing concern that freshwater diversions of the Mississippi River into brackish or saltwater systems could reduce salinity to a level that allows entrained carp to navigate freshwater plumes to uninvaded rivers. To help quantify this risk, we conducted an Arrival Assessment that estimates the number of invasive carp that will enter a receiving waterbody through a single freshwater diversion event. A case study using the Bonnet Carré Spillway is presented here to illustrate how water managers and spillway operators can derive predictions for a specific spillway and how mitigative steps can be taken to target the most influential parameters and help reduce the number of carp that pass. The findings of this case study suggest that, for an average spillway opening event, the number of invasive carp that pass through the Bonnet Carré Spillway is higher than many water managers may be willing to accept. This Arrival Assessment serves as the first of three components within a broader, forthcoming quantitative risk assessment that will also consider the number of carp that survive (Survival Assessment) to reach a suitable, uninvaded river for reproduction and population sustainment (Establishment Assessment) and determine the magnitude and uncertainty of the risk of introduction to uninvaded waters downstream from a freshwater diversion that forms a hydrological connection to a source waterbody inhabited by invasive carp.
Freshwater darters belonging to the Orangethroat Darter species complex, or Ceasia , are widely distributed in the Central and Southern United States, with ranges that span both glaciated as well as unglaciated regions. Up to 15 species have been recognized in the complex, with one, Etheostoma spectabile , having a widespread northern distribution and another, E. pulchellum , having a sizeable southern distribution. The other species in the complex have much more restricted distributions in unglaciated regions of the Central Highlands. We sampled 384 darters from 52 sites covering much of the range of Ceasia and evaluated patterns of genetic diversity, genetic structure, and pre‐ and post‐glacial patterns of range contraction and expansion. We anticipated finding much stronger signals of genetic differentiation and diversification in unglaciated regions, given the higher species diversity and levels of endemism reported there. Surprisingly, microsatellite genotyping revealed two well‐differentiated genetic clusters of E. spectabile in samples from glaciated regions, one confined to the Illinois River basin and another found in the Wabash drainage and Great Lakes tributaries. This suggests that there was expansion from two isolated glacial refugia, with little subsequent post‐glacial gene flow. Fish collected from throughout the unglaciated region were less genetically differentiated. Fish assigned to E. burri and E. uniporum based on collection sites and morphological characters were not genetically differentiated from E. spectabile samples from the region. Hybridization and introgression occurring in the Central Highlands may confound genetic delineation of species in this region of high endemism and diversity.
The precise mechanism of resistance to anti-cancer drugs such as platinum drugs is not fully revealed. To reveal the mechanism of drug resistance, the molecular networks of anti-cancer drugs such as cisplatin, carboplatin, oxaliplatin, and arsenic trioxide were analyzed in several types of cancers. Since diffuse-type stomach adenocarcinoma, which has epithelial–mesenchymal transition (EMT)-like characteristics, is more malignant than intestinal-type stomach adenocarcinoma, the gene expression and molecular networks in diffuse- and intestinal-type stomach adenocarcinomas were analyzed. Analysis of carboplatin revealed the causal network in diffuse large B-cell lymphoma. The upstream regulators of the molecular networks of cisplatin-treated lung adenocarcinoma included the anti-cancer drug trichostatin A (TSA), a histone deacetylase inhibitor. The upstream regulator analysis of cisplatin revealed an increase in FAS, BTG2, SESN1, and CDKN1A, and the involvement of the tumor microenvironment pathway. The molecular networks were predicted to interact with several microRNAs, which may contribute to the identification of new drug targets for drug-resistant cancer. Analysis of oxaliplatin, a platinum drug, revealed that the SPINK1 pancreatic cancer pathway is inactivated in ischemic cardiomyopathy. The study showed the importance of the molecular networks of anti-cancer drugs and tumor microenvironment in the treatment of cancer resistant to anti-cancer drugs.
Cyber hardening systems, such as intrusion detection and firewalls, are no longer sufficient to keep cyber systems safe from today’s smart and well-resourced attackers. However, these systems have high false-positive rates, and even experts may find it difficult to understand the reasons behind their predictions. With the emergence of Internet of Things (IoT) ecosystems, these systems need to address data heterogeneity and the complexity of IoT networks. Developing a cyber-resilient intrusion discovery model is challenging, as it must adapt to zero-day exploits in real-time, and respond strategically to retain the vital operations of systems in the event of exploits and system failures. The assessment of cyber resilience becomes increasingly difficult due to the uncertainties of predicting security events and system failures in real time. The relationship between security, robustness, and vulnerabilities is focused on preventing IoT system degradation and maintaining acceptable levels of functionality before and after occurring uncertain events. To address these challenges, we propose an explainable cyber intrusion discovery framework to make the model transparent and trustworthy, along with the capability of evaluating its cyber resilience using a cyber threat matrix. We employ an explainable convolutional neural network-based transfer learning model to detect uncertain events including security events and failures. Our proposed solution produces high detection rates for the different families of uncertain events. These results demonstrated that deep transfer learning is effective in discovering and assessing cyber-attacks in IoT networks. For this analysis, we used the TON_IoT dataset, and our model produced an average detection rate of 97%.
Water security in arid and semi-arid Middle Eastern climates has been severely impacted by effects of climate change such as reduced precipitation, diminished storage, increased evapotranspiration, and prolonged heat waves. These climate effects are compounded in Iraq, where populations, agriculture, industry, and energy rely heavily on varying transboundary water flows to meet water demands. Iraq’s most profitable sector, energy, is especially threatened by insufficient water supply, which complicates government decision making in energy infrastructure development. The goal of this paper is to develop a scenario-based multi-criteria analysis framework to prioritize infrastructure investments in the context of climate change and scarcity of natural resources. Infrastructure facilities are evaluated against social, economic, climate, and hydrologic criteria across a set of disruptive climatological, economic, and social scenarios to identify robust initiatives and the most and least disruptive scenarios to the system. A particular innovation of this paper is the use of hydrology data derived from satellites in determining water scarcity impact on individual energy facilities. The methods are demonstrated for a critical sector of Iraq’s economy: oil and natural gas. The demonstration includes 13 system order criteria, 44 oil and gas initiatives within Iraq, and seven risk scenarios. The results include an accounting of the most and least disruptive scenarios to energy sector priorities and scenario-based system orderings to guide stakeholders in investment prioritization.
Basal bark treatment with triclopyr butoxyethyl ester is used to control woody invasive plants, including Brazilian peppertree ( Schinus terebinthifolius Raddi). However, the ester formulation cannot be applied where standing water is present, which includes wetlands where S. terebinthifolius is found. In 2009, a low-volatile acid formulation of triclopyr was labeled for use in aquatic sites which allows for basal bark applications when standing water is present. This formulation may have utility for controlling woody plants in standing water. However, anecdotal observations of injury to non-target plants following applications during periods of inundation have been reported. To address this, mesocosm studies were conducted to assess non-target injury through triclopyr root exudation or release from the surface of treated stems via flooding. Mesocosms contained S. terebinthifolius as the treated target while sugarberry ( Celtis laevigata Willd.), buttonbush ( Cephalanthus occidentalis L.), and red maple ( Acer rubrum L.) were included as non-targets. In the first study, the pathway of root exudation for non-target injury following triclopyr (34 g L ⁻¹ ) basal bark application was isolated with activated charcoal placed at the soil surface. In the second study, mesocosms were flooded to assess triclopyr release from the surface of treated stems and subsequent non-target injury. Defoliation of non-target species post-treatment was ≤ 8% and triclopyr was detected at ≤ 5 µg L ⁻¹ in mesocosm wells when activated charcoal was present. Post-treatment non-target defoliation up to 92%, coupled with triclopyr concentrations in surface waters and wells as high as 4,637 µg L ⁻¹ , indicated triclopyr movement as a result of flooding. Additionally, triclopyr non-target injury from soil activity independent of flooding was observed. These findings provide limited evidence of triclopyr root exudation but considerable evidence of triclopyr release during flooding following basal bark treatment and support a cautionary approach to basal bark application when standing water is present.
Civil infrastructure will be essential to face the interlinked existential threats of climate change and rising resource demands while ensuring a livable Anthropocene for all. However, conventional infrastructure planning largely neglects the contributions and maintenance of Earth’s ecological life support systems, which provide irreplaceable services supporting human well-being. The stability and performance of these services depend on biodiversity, but conventional infrastructure practices, narrowly focused on controlling natural capital, have inadvertently degraded biodiversity while perpetuating social inequities. Here, we envision a new infrastructure paradigm wherein biodiversity and ecosystem services are a central objective of civil engineering. In particular, we reimagine infrastructure practice such that 1) ecosystem integrity and species conservation are explicit objectives from the outset of project planning; 2) infrastructure practices integrate biodiversity into diverse project portfolios along a spectrum from conventional to nature-based solutions and natural habitats; 3) ecosystem functions reinforce and enhance the performance and lifespan of infrastructure assets; and 4) civil engineering promotes environmental justice by counteracting legacies of social inequity in infrastructure development and nature conservation. This vision calls for a fundamental rethinking of the standards, practices, and mission of infrastructure development agencies and a broadening of scope for conservation science. We critically examine the legal and professional precedents for this paradigm shift, as well as the moral and economic imperatives for manifesting equitable infrastructure planning that mainstreams biodiversity and nature’s benefits to people. Finally, we set an applied research agenda for supporting this vision and highlight financial, professional, and policy pathways for achieving it.
Command (i. e., static) detonation is critical for testing munitions early in the acquisition process, however its representation of energetic residues produced during live fire has not yet been assessed. Here we measured energetic residue deposition rates on snow from live fire of 60 mm and 81 mm IMX‐104 mortar munitions and then compared results with previous command‐detonation tests of the same munitions. Mean live‐fire deposition rates of IMX‐104 compounds were: 3800 mg NTO, 34 mg DNAN, 12 mg RDX, and 1.9 mg HMX per 60 mm cartridge (n=9); and 8000 mg NTO, 60 mg DNAN, 20 mg RDX, and 2 mg HMX per 81 mm cartridge (n=13). The predominant residue compound NTO was accurately estimated by command detonation for the 60 mm munition (p=0.92) but was significantly underestimated for the 81 mm munition (p<0.0001). The minor residues of DNAN and RDX were relatively well estimated by command detonation for the 81 mm munition (p=0.07 and p=0.014, respectively), but both were significantly underestimated (p<0.0001) for the 60 mm munition. Despite some of these differences, the ability demonstrated here for command detonation to predict live‐fire residue deposition rates to the correct order‐of‐magnitude supports its utility in assessing environmental impact.
Although the Caribbean's Small Island Developing States (SIDS) minimally contribute to global greenhouse gas emissions, they face disproportionate climate risks and are particularly susceptible to systemic economic threats posed by climate change and subsequent increases in climate variability. Historically, strategic programs and investments have sought to develop more robust and adaptive engineered systems to absorb climate threats. However, such initiatives are limited and under‐resourced in SIDS’ context. This article reviews existing climate strategies in the Caribbean and then critically examines current gaps and barriers relating to climate impact knowledge, needs, and implementation. This examination can assist Caribbean SIDS leadership to identify opportunities to transition from a vulnerability‐reducing mindset to one of resilience and transformative adaptation to improve long‐term economic outlooks, social welfare, and environmental stewardship despite recurring and escalating climate risks.
While cockroaches are commonly exhibited in zoos and museums, studied in research laboratories, and even kept as pets, scientifically based guidelines for their euthanasia are lacking. This study assessed euthanasia techniques in four species of cockroaches (Dubia ( Blaptica dubia ), red runner ( Shelfordella lateralis ), Madagascar hissing ( Gromphadorhina portentosa ), and giant cave ( Blaberus giganteus )). In an initial pilot study, two hundred fifty adult Dubia cockroaches were exposed in groups of ten to a cotton ball soaked with 2 mL of isoflurane in a 1 L air-tight chamber. Thirty minutes beyond loss of any individual movement, groups were exposed to one of the following secondary treatments: freezing at −18 °C or −80 °C from 0.25 to 24 hours; immersion in 10% neutral buffered formalin, 70% isopropyl alcohol, or reverse osmosis water for 0.25 or 0.5 hours; or intracoelomic injection of potassium chloride (456 mEq/kg) or pentobarbital-based euthanasia solution (3.9 g/kg). A control group remained in the air-tight isoflurane chamber for 24 hours. Following all treatments, cockroaches were monitored for an additional 24 hours for spontaneous movement. Irreversible loss of movement was considered synonymous with irreversible loss of consciousness (death). Across all species, isoflurane anesthesia followed by either 70% isopropyl alcohol immersion for 0.25 or 0.5 hours or isoflurane exposure for 24 hours resulted in euthanasia in 100% of cockroaches. This study is the first evaluation of American Veterinary Medical Association-recommended euthanasia protocols in cockroaches.
The Mississippi River Delta (MRD) is one of the largest wetlands in the world and is experiencing widespread dieback of its most prevalent plant species, Phragmites australis. The potential for revegetation of dieback sites was assessed by planting three genetically distinct lineages of P. australis at seven sites in the MRD that varied in water depth. These lineages include Delta, the most prevalent in the MRD, EU, a highly invasive lineage, and Gulf, a common lineage of the Gulf Coast and southern United States. Three additional wetland species were planted at a subset of these sites. Plantings were monitored for 32 months during which time, we surveyed plantings for survival, growth and infestation by a scale insect that has been implicated in P. australis dieback. Survivorship differed considerably among plant types and by 6 months, Delta, Gulf and California bulrush (Schoenoplectus californicus) had twice the survivorship of the other plant types. By the end of the study, Delta, Gulf and bulrush were the only plant types alive, with Delta persisting in more than twice as many sites and having > 6 times more area of coverage as Gulf and bulrush. For all P. australis lineages, water depth was negatively related to survivorship. Finally, although scale insects achieved twice the abundance on Delta than the other lineages, we found no evidence that scales were inhibiting the growth and survival of P. australis. Despite potential negative legacy effects of dieback, Delta can be used revegetate shallow-water sites within a year following dieback.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
421 members
Rajeev Agrawal
  • Information Technology Laboratory
Natàlia Garcia-Reyero
  • Environmental Laboratory
Kurt A Gust
  • Environmental Laboratory
Guilherme R Lotufo
  • Environmental Laboratory
Ping Gong
  • Environmental Laboratory
3909 Halls Ferry Road, 39180-3188, Vicksburg, MS, United States
Head of institution
Dr. David Pittman