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Background Nest construction is a key element of avian reproductive behaviour and the result is often a complex structure that is used for incubation of eggs, which represents an extended phenotype. It is known that nest construction is a plastic behaviour but the extent to which plasticity is observed in a single species with a wide geographical distribution is largely unknown. This study sought to better understand variation in nest size and composition across a very wide geographical area. The hypothesis suggested that location would affect size but not composition of nests of the European Pied Flycatcher ( Ficedula hypoleuca ). Methods Nests and reproductive data were collected from seventeen study sites, spread over 6° of latitude and 3.3° of longitude on the island of Great Britain. Dimensions of nests were measured before they were deconstructed to determine the masses and types materials used in the outer nest and the cup lining. Results Geographical variation was observed in base thickness of nests but not many other dimensions. Nests varied in composition but were mainly made of leaf, moss, bark, grass, root and fern. Moss was used more to the north and east of the study area compared with more leaf mass towards the south and west. The species of leaf and bark used in the nests varied between geographical locations. Additionally, the use of leaves or bark from a particular tree species did not reflect the incidence of the tree species in the immediate territory. Conclusions This study showed that nest composition was affected by geographical location over a wide area. Variation between nests at each location was high and so it was concluded that differences in nest composition reflect individual selection of materials but evidence is such that it remains unclear whether this is deliberate to fulfil a specific role in the nest, or simply opportunistic with birds simply picking up materials with the appropriate characteristics as they find them outside their nestbox.

Continuing trends of declining bottom-water dissolved oxygen (BWDO) in coastal oceans are a threat to marine organisms, especially the benthos, and in the northern Gulf of Mexico (nGOM), the hypoxic area is expected to expand. Within-sediment vertical functional metric responses of macrobenthos were examined in four depth strata at four sites with different histories of exposure to seasonal hypoxia. The sites H7, D5, E4, and A6 between 30 and 39-m water depth represented a historical oxygen stress gradient from 5.4 to 2.1 mg L⁻¹ BWDO (mid-summer 11-year mean), from which macrobenthos were sampled in spring and late summer 2009 and in mid-summer in 2010. High abundance together with high biomass and production potential within upper strata under low BWDO stress supports the primacy of a numerically driven response in this system. Total abundance decreased along the BWDO stress gradient, and the lowest abundance coincided at the highest stress (MaxStress) site together with the highest proportion of opportunists, the smallest mean size, and the shortest turnover time. Accordingly, the relative abundance of opportunists within the upper two strata increased while surface deposit feeders decreased with greater hypoxic stress. Notwithstanding the proportion of opportunists, functional metrics generally decreased across the BWDO stress gradient within the upper strata, and metrics generally varied inversely between upper and lower strata. The findings underscore how vertical benthos distribution patterns reflect the BWDO exposure regime and how secondary production varies as an indicator of trophic transfer potential and organic matter processing within this system.

Nestboxes are widely provided as nesting sites for hole-nesting birds, yet the relative contribution of nestbox characteristics and habitat quality in determining the occupancy rates and breeding success of birds remains unclear. We provided nestboxes in deciduous woodlands in England and examined if those nestboxes were erected in random orientations and whether the orientation of nestboxes and habitat quality, in the form of tree density, influenced their occupation by, and breeding success of, Blue Tits , Great Tits and Pied Flycatchers . We found that first, the nestboxes were erected non-randomly orientated towards the north and east, and away from the south and west. Second, the occupation rates of none of the species was related to nestbox orientation or tree density. Third, the breeding success of neither Blue Tits nor Great Tits varied with tree density but did vary with nestbox orientation. Blue Tit hatching success and fledging success was higher in nestboxes facing south than in other directions whilst in Great Tits, clutch sizes, hatching success and fledging success was higher in nestboxes facing south than nestboxes facing other directions. Our results suggest that nestbox characteristics, such as orientation, have more influence on the reproductive success of passerines than habitat quality. This further suggests that conservationists should orientate nestboxes southwards in order to maximise their benefit to birds in temperate climates during the breeding season.

Food sources and feeding selectivity of numerically dominant asteroids and holothurians collected with trawls from the Venezuela Basin, Caribbean Sea, were investigated by means of gut analysis. Particle-size distributions of gut contents of Thoracaster cylindratus, Styracaster horridus, Psychropotes semperiana, and Pseudostichopus atlanticus and of sediments were compared from 3 different sedimentary provinces in the Venezuela Basin (3,410–5,062 m depth). Megabenthic echinoderms (megabenthos) from the 2 shallower provinces had gut contents with particle-size distributions almost identical to that of the top 5 mm of sediment and conspicuously coarser than sediment below 5 mm depth. Gut contents of echinoderms from the deepest province had a higher percent of coarse and medium sand-size foraminiferan tests than that of surrounding sediment. Microscopic examination of the coarse fractions revealed intact pelagic foraminiferan tests in the guts of megabenthos collected from 5,000 m depth whereas pelagic foraminiferan tests from surrounding surface sediments were fragmented and eroded. The possibility of recently settled fecal pellets from the pelagic realm as a food source is suggested. These data suggest that some bulk deposit feeders skim the surface of the sea bottom feeding on the uppermost layer of sediment; thus, they selectively ingest the more nutritive, uppermost layer of sediment in the deep sea without modifying feeding behavior per se.

The presence of mines in littoral regions is a major threat to military operations and civilian shipping, particularly when mines are buried or partially buried. To meet this threat, the U.S. Navy is supporting programs to predict mine burial and to correlate mine burial with the hydrodynamic processes and sediment types that affect burial. The goal is to develop and validate mine burial models for use in strategic and tactical Mine CounterMeasures (MCM) planning and operations. This article examines activities and programs to develop and validate mine burial models for use in strategic and tactical MCM planning and operations.

Improvements in temporal resolution of single-photon detectors enable increased data rates and transmission distances for both classical and quantum optical communication systems, higher spatial resolution in laser ranging, and observation of shorter-lived fluorophores in biomedical imaging. In recent years, superconducting nanowire single-photon detectors (SNSPDs) have emerged as the most efficient time-resolving single-photon-counting detectors available in the near-infrared, but understanding of the fundamental limits of timing resolution in these devices has been limited due to a lack of investigations into the timescales involved in the detection process. We introduce an experimental technique to probe the detection latency in SNSPDs and show that the key to achieving low timing jitter is the use of materials with low latency. By using a specialized niobium nitride SNSPD we demonstrate that the system temporal resolution can be as good as 2.6 ± 0.2 ps for visible wavelengths and 4.3 ± 0.2 ps at 1,550 nm.Knowledge about detection latency provides a guideline to reduce the timing jitter of niobium nitride superconducting nanowire single-photon detectors. A timing jitter of 2.6 ps at visible wavelength and 4.3 ps at 1,550 nm is achieved.

Groundwater discharge to streams is a nonpoint source of nitrogen (N) that confounds N mitigation efforts and represents a significant portion of the annual N loading to watersheds. However, we lack an understanding of where and how much groundwater N enters streams and watersheds. Nitrogen concentrations at the end of groundwater flowpaths are the culmination of biogeochemical and physical processes from the contributing land area where groundwater recharges, within the aquifer system, and in the near-stream riparian area where groundwater discharges to streams. Our research objectives were to quantify the spatial distribution of N concentrations at groundwater discharges throughout a mixed land-use watershed and to evaluate how relationships among contributing and riparian land cover, modeled aquifer characteristics, and groundwater discharge biogeochemistry explain the spatial variation in groundwater discharge N concentrations. We accomplished this by integrating high-resolution thermal infrared surveys to locate groundwater discharge, biogeochemical sampling of groundwater, and a particle tracking model that links groundwater discharge locations to their contributing area land cover. Groundwater N loading from groundwater discharges within the watershed varied substantially between and within streambank groundwater discharge features. Groundwater nitrate concentrations were spatially heterogeneous ranging from below 0.03–11.45 mg-N/L, varying up to 20-fold within meters. When combined with the particle tracking model results and land cover metrics, we found that groundwater discharge nitrate concentrations were best predicted by a linear mixed-effect model that explained over 60% of the variation in nitrate concentrations, including aquifer chemistry (dissolved oxygen, Cl − , SO 4 2− ), riparian area forested land cover, and modeled physical aquifer characteristics (discharge, Euclidean distance). Our work highlights the significant spatial variability in groundwater discharge nitrate concentrations within mixed land-use watersheds and the need to understand groundwater N processing across the many spatiotemporal scales within groundwater cycling.

In the Gramineae, the cyclic hydroxamic acids 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) and 2,4-dihydroxy-7-methoxy-1 ,4-benzoxazin-3-one (DIMBOA) form part of the defense against insects and microbial pathogens. Five genes, Bx1 through Bx5, required for DIBOA biosynthesis in maize. The functions of these five genes, clustered on chromosome 4, were demonstrated in vitro. Bx1 encodes a tryptophan synthase alpha homolog that catalyzes the formation of indole for the production of secondary metabolites rather than tryptophan, thereby defining the branch point from primary to secondary metabolism. Bx2 through Bx5 encode cytochrome P450-dependent monooxgenases that catalyze four consecutive hydroxylations and one ring expansion to the highly oxidized DIBOA

In cases of suspected meningitis or encephalitis that were difficult to diagnose, metagenomic sequencing of CSF was used to attempt to determine the etiologic agent. Metagenomic sequencing was able to determine a likely pathologic agent that was clinically actionable in some cases.

Eating disorders are a group of psychiatric conditions that involve pathological relationships between patients and food. The most prolific of these disorders are anorexia nervosa, bulimia nervosa, and binge eating disorder. The current standard of care involves psychotherapy, pharmacotherapy, and the management of comorbid conditions, with nutritional rehabilitation reserved for severe cases of anorexia nervosa. Unfortunately, many patients often fail to respond, leaving a concerning treatment gap between the current and requisite treatments for eating disorders. To better understand the neurobiology underlying these eating disorders, investigations have been undertaken to characterize the activity of various neural networks, primarily those activated during tasks of executive inhibition, reward processing, and self-reference. Various neuromodulatory techniques have been proposed to stimulate these networks with the goal of improving patients’ BMI and mental health. The aim of this review is to compile a comprehensive summarization of the current literature regarding the underlying neural connectivity of anorexia nervosa, bulimia nervosa, and binge eating disorder as well as the numerous neuromodulatory modalities that have been investigated. Importantly, we aimed to summarize the most significant clinical trials to date as well as to provide an updated assessment of the role of deep brain stimulation, summarizing numerous recently published clinical studies that have greatly contributed to the literature. In this review, we found therapeutic evidence for transcranial magnetic stimulation and transcranial direct current stimulation in treating individuals suffering from anorexia nervosa, bulimia nervosa, and binge eating disorder. We also found significant evidence for the role of deep brain stimulation, particularly as an escalatory therapy option for the those who failed standard therapy. Finally, we hope to provide promising directions for future clinical investigations.