•Passive acoustic techniques can be used to identify and quantify underwater gas release.•We propose an adaptive single bubble identification technique, incorporating bubble acoustic characteristics ...of time, frequency and strength.•In a controlled gas release experiment, the bubble radius is acoustically determined as 0.15–0.3 cm, and optically determined as 0.2–0.5 cm.•The gas flux is acoustically estimated as 32–88 kg/day in response to a known gas injection flow rate 143 kg/day.
Passive acoustic techniques can be used to identify and quantify underwater gas release at natural sites, or at locations related to anthropogenic activities. There are still significant issues in extracting bubble signals from background noise, particularly for bubble counting and sizing techniques relying on inversion of the time-averaged acoustic spectrum. In this work we propose an adaptive single bubble identification technique, which incorporates bubble acoustic characteristics including pulsation time interval, frequency bandwidth and radiation strength. The method applies a cross-spectrogram, enabling an increase in signal-to-noise ratio resulting in a reduction of the false alarm rate on bubble identification. We demonstrate this technique using an array of hydrophones to determine the bubble size distribution and gas flux at a controlled CO2 release site, 4 m beneath the seabed, at 120 m water depth in the central North Sea. The results show that the bubble radius, as estimated using acoustics has a distribution with a peak in the 0.15–0.3 cm range, while an estimate based on optical method suggests a range of 0.2–0.5 cm. The gas flux is acoustically estimated as 32–88 kg/day in response to a known gas injection flow rate 143 kg/day, indicating 22–62% of the injected CO2 is emitted from the seabed in gaseous form, with the remainder being trapped, or dissolved.
According to many prognostic scenarios by the Intergovernmental Panel on Climate Change (IPCC), a scaling-up of carbon dioxide (CO2) capture and storage (CCS) by several orders-of-magnitude is ...necessary to meet the target of ≤2 °C global warming by 2100 relative to preindustrial levels. Since a large fraction of the predicted CO2 storage capacity lies offshore, there is a pressing need to develop field-tested methods to detect and quantify potential leaks in the marine environment. Here, we combine field measurements with numerical models to determine the flow rate of a controlled release of CO2 in a shallow marine setting at about 119 m water depth in the North Sea. In this experiment, CO2 was injected into the sediment at 3 m depth at 143 kg d-1. The new leakage monitoring tool predicts that 91 kg d-1 of CO2 escaped across the seafloor, and that 51 kg d-1 of CO2 were retained in the sediment, in agreement with independent field estimates. The new approach relies mostly on field data collected from ship-deployed technology (towed sensors, Acoustic Doppler current profiler—ADCP), which makes it a promising tool to monitor existing and upcoming offshore CO2 storage sites and to detect and quantify potential CO2 leakage.
•Combination of towed sensors and numerical simulations quantified the CO2 leakage.•64% of CO2 injected at 3-m depth in the sediment leaked into bottom water.•Gas-phase measurements of chemical tracers validated the bubble dissolution model.
•Improved local labor market opportunities for low-skilled individuals may reduce criminal behavior by increasing its opportunity cost.•This study explores the impact of one of the most prominent ...low-wage labor policies in the United States — the minimum wage — on teenage and young adult arrests.•Using data from the 1998–2016 Uniform Crime Reports and a difference-in-differences approach, we find that a 1 percent increase in the minimum wage is associated with a 0.2 percent increase in property crime arrests among 16-to-24-year-olds, an effect driven by larceny-related arrests.•Supplemental analyses of “affected workers” in the National Longitudinal Survey of Youth 1997 show that increases in the minimum wage increase property crime for low-wage workers.•Minimum wage-induced job loss may be a mechanism to explain increases in larceny arrests.•A $15 Federal minimum wage, proposed as part of the Raise the Wage Act of 2021, could generate median criminal externality costs of approximately $766 million.
The availability of higher-paying jobs for low-skilled individuals has been documented to reduce crime. This study explores the impact of one of the most prominent labor policies designed to provide higher wages for low-skilled workers — the minimum wage — on teenage and young adult arrests. Using data from the 1998–2016 Uniform Crime Reports and a difference-in-differences approach, we find that a 1 percent increase in the minimum wage is associated with a 0.2 to 0.3 percent increase in property crime arrests among 16-to-24-year-olds, an effect driven by an increase in larceny-related arrests. The magnitudes of our estimated elasticities suggest that a $15 Federal minimum wage, proposed as part of the Raise the Wage Act, could generate approximately 309,000 additional larcenies. Job loss emerges as an important mechanism to explain our findings, and supplemental analyses of affected workers in the National Longitudinal Survey of Youth 1997 show that this effect is concentrated among workers bound by minimum wage increases. Finally, we find no evidence that minimum wage hikes impact violent crime arrests.
We describe a unique microsporidian species that infects the green stink bug, Chinavia hilaris; the brown marmorated stink bug, Halyomorpha halys; the brown stink bug, Euschistus servus; and the ...dusky stink bug, Euschistus tristigmus. All life stages are unikaryotic, but analysis of the consensus small subunit region of the ribosomal gene places this microsporidium in the genus Nosema, which historically has been characterized by diplokaryotic life stages. It is also characterized by having the reversed arrangement of the ribosomal gene (LSU -ITS- SSU) found in species within the "true Nosema" clade. This microsporidium is apparently Holarctic in distribution. It is present in H. halys both where it is native in Asia and where it is invasive in North America, as well as in samples of North American native C. hilaris collected prior to the introduction of H. halys from Asia. Prevalence in H. halys from mid-Atlantic, North America in 2015-2016 ranged from 0.0% to 28.3%, while prevalence in C. hilaris collected in Illinois in 1970-1972 ranged from 14.3% to 58.8%. Oral infectivity and pathogenicity were confirmed in H. halys and C. hilaris. Morphological, ultrastructural, and ecological features of the microsporidium, together with a molecular phylogeny, establish a new species named Nosema maddoxi sp. nov.
Research pertaining to the two closely-related microsporidian genera Nosema and Vairimorpha is hindered by inconsistencies in species differentiation within and between the two clades. One proposal ...to better delimit these genera is to restructure the Nosema around a "True Nosema" clade, consisting of species that share a characteristic reversed ribosomal DNA operon arrangement and small subunit (SSU) ribosomal DNA sequences similar to that of the Nosema type species, N. bombycis. Using this framework, we assess two distinct microsporidia recovered from the forest insect Bruce spanworm (Operophtera bruceata) by sequencing their SSU and internal transcribed spacer regions. Phylogenetic analyses place one of our isolates within the proposed True Nosema clade close to N. furnacalis and place the other in the broader Nosema/Vairimorpha clade close to N. thomsoni. We found that 25% of Bruce spanworm cadavers collected over the four-year study period were infected with microsporidia, but no infections were detected in cadavers of the Bruce spanworm's invasive congener, the winter moth (O. brumata), collected over the same period. We comment on these findings as they relate to the population dynamics of the Bruce spanworm-winter moth system in this region, and more broadly, on the value of ribosomal DNA operon arrangement in Nosema systematics.
Significance
Dopamine and glutamate in the prefrontal cortex are important substrates of higher cognitive functions, which are impaired in neuropsychiatric disorders. As regards glutamatergic ...pathways, a role for the NMDA receptor coagonist
d
-serine has been highlighted, yet its relationship to dopaminergic transmission remains unclear. In this study, we reveal that
d
-serine plays a pivotal role in the modulation by dopamine of NMDA receptor activity and cognitive performance in the prefrontal cortex. Comprehensive evidence for this interaction is provided at the synaptic, neuronal, network, and behavioral levels. These observations are of relevance to the pathophysiology and treatment of cognitive impairment in numerous disorders involving disruption of the frontocortical dialogue between dopamine and glutamate.
Prefrontal control of cognitive functions critically depends upon glutamatergic transmission and N-methyl D-aspartate (NMDA) receptors, the activity of which is regulated by dopamine. Yet whether the NMDA receptor coagonist
d
-serine is implicated in the dopamine–glutamate dialogue in the prefrontal cortex (PFC) and other brain areas remains unexplored. Here, using electrophysiological recordings, we show that
d
-serine is required for the fine-tuning of glutamatergic neurotransmission, neuronal excitability, and synaptic plasticity in the PFC through the actions of dopamine at D
1
and D
3
receptors. Using in vivo microdialysis, we show that D
1
and D
3
receptors exert a respective facilitatory and inhibitory influence on extracellular levels and activity of
d
-serine in the PFC, with actions expressed primarily via the cAMP/protein kinase A (PKA) signaling cascade. Further, using functional magnetic resonance imaging (fMRI) and behavioral assessment, we show that
d
-serine is required for the potentiation of cognition by D
3
R blockade as revealed in a test of novel object recognition memory. Collectively, these results unveil a key role for
d
-serine in the dopaminergic neuromodulation of glutamatergic transmission and PFC activity, findings with clear relevance to the pathogenesis and treatment of diverse brain disorders involving alterations in dopamine–glutamate cross-talk.
The Affordable Care Act’s dependent coverage mandate (DCM) induced approximately 2 million young adults to join parental employer-sponsored health insurance plans. This study is the first to explore ...the impact of the DCM on crime, a potentially important externality. Using data from the National Incident-Based Reporting System, we find that the DCM induced a 2–5 percent reduction in property crime incidents involving young adult arrestees ages 22–25 relative to those ages 27–29. This finding is supported by supplemental analysis using data from the Uniform Crime Reports. An examination of the underlying mechanisms suggests that declines in large out-of-pocket expenditures for health care, increased educational attainment, and increases in cohabitation of parents and adult children may explain these declines in crime. Back-of-the-envelope calculations suggest that the DCM generated approximately $371–$512 million in annual social benefits from crime reduction among young adults.
The Siberian hamster provides a physiological model for understanding the hypothalamic control of energy metabolism as it undergoes annual photoperiod‐regulated cycles of body weight (i.e. fattening ...in summer, and catabolism of fat stores in winter). As a first step to investigate whether enhanced serotonergic (5‐HT) tone might underlie the catabolic processes in short days, we investigated whether serotonergic stimulation can produce catabolic actions in fat hamsters housed in long days. Acute treatment with the serotonin reuptake inhibitor (+/–) fenfluramine (8 mg/kg, i.p.) produced a prolonged, dose‐dependent reduction in food intake in both photoperiods. Behavioural observations and radiotelemetry analyses revealed that this anorectic effect of fenfluramine was associated with short‐term increases in locomotor activity and in core body temperature. In a subsequent series of studies, hamsters were pretreated with the 5‐HT2C receptor antagonist SB242084 (4 mg/kg, i.p.). This 5‐HT2C receptor antagonist completely blocked the anorectic actions of fenfluramine, but did not decrease the hyperthermia or hyperlocomotion induced by fenfluramine; thus, the anorectic actions of fenfluramine probably reflect actions via the 5‐HT2C receptor. Consistent with these observations, treatment of hamsters with the 5‐HT2C receptor agonist VER 3323 (10 mg/kg, i.p.) or the 5‐HT1B/2C receptor agonist mCPP (3 mg/kg, i.p.) reduced food intake. The response to manipulation of serotonergic pathways was not affected by the ambient photoperiod in any of these studies. We conclude that the anorectic actions of fenfluramine are not an indirect consequence of serotonergic actions on arousal pathways, and that its actions on feeding in the Siberian hamster are most likely to be mediated by the 5‐HT2C receptor.
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